Reasons for Judgment

Released: June 24, 2025

Court: Ontario Superior Court of Justice

Between:
Kathleen MacNeill, Plaintiff
and
McDonald’s Restaurants of Canada Limited, Defendant

Heard: January 8, 9, 10, 13, 14, 15, 16, 17 and 20, 2025 (submissions received in writing)

Appearances:
Lane Foster and Kenneth Ciupka, for the Plaintiff
Edward Key and Emma Tomas, for the Defendant

Judge: Sean McCarthy

Introduction

[1] The Plaintiff seeks damages for injuries arising from an incident that took place on October 1, 2015 (the “incident”).

[2] On that date, the Plaintiff ingested liquid from a paper coffee cup containing a diluted deliming agent (the “delimer solution”) served to her at the drive-thru of a McDonald’s restaurant located on Coldwater Road in Orillia (“McDonald’s”).

[3] Liability for the incident is not disputed.

[4] At the time of the incident, the Plaintiff was employed as a customer service representative (“CSR”) at Nordia Inc., a call centre located in Orillia.

The Plaintiff’s Position

[5] The Plaintiff advances a claim for damages under the following headings and in the following ranges:

• General damages for pain and suffering: $100,000 to $125,000
• Past Loss of Income: $297,742 to $344,555
• Future Loss of Income: $1,043,037 to $1,101,484
• Loss of Competitive Advantage (in the alternative): $80,000 to $150,000
• Future Care Costs: $222,432

[6] The Plaintiff contends that as a result of ingesting and swallowing the delimer solution, she sustained chemical or caustic burns to her throat, which resulted in a condition called Muscle Tension Dysphonia (“MTD”), an upper aerodigestive tract injury. The condition is exacerbated by speaking, eating, and drinking. The Plaintiff also contends that these injuries have resulted in ongoing chronic pain in her throat and esophageal area accompanied by a raspy, broken voice. These physical injuries have been compounded by the development of psychological conditions or the exacerbation of pre-existing psychological problems.

[7] The Plaintiff’s attempt to return to the CSR position met with failure. She has been unable to pursue other suitable employment. As a result, she has suffered both past and future loss of income. Complicating her situation are her pre-existing physical impairments from a 2009 motor vehicle accident (the “MVA”), which left her with physical limitations disabling her from physically demanding work.

[8] The Plaintiff was able to secure employment as a CSR in May 2015. It was a position for which she was entirely suited. The ongoing and permanent symptoms from the incident now render her unable to engage in prolonged talking or voice use, both of which are essential tasks of a CSR. The combined effect of her injuries from both the MVA and the incident has left her unemployable. She will now suffer a complete loss of income into the future until the date when she would have otherwise retired. At the very least, she will experience an ongoing and permanent loss of competitive advantage and/or loss of earning capacity in the event she is able to return to some alternative form of employment.

[9] The negative impact of the injuries on both the Plaintiff’s previous lifestyle and her ability to work is attested to by her friends and family.

[10] These conditions and impairments require ongoing treatment, goods, and services, which have been identified and quantified by Marla Tennen, a registered nurse and rehabilitation consultant.

The Defendant’s Position

[11] The Defendant acknowledges that the Plaintiff consumed a delimer solution containing a quantity of a product called Kay Delimer, which was used to clean and “de-lime” its coffee-making machines. That said, the delimer solution the Plaintiff ingested was food-safe, with a pH in the same range as lemon juice. The delimer solution could not have caused the physical injuries alleged.

[12] The Plaintiff has failed to establish that ingesting the delimer solution was a “but for” cause of her MTD. There are other causes for the condition, completely unrelated to the incident.

[13] The Defendant asserts that the Plaintiff was an unreliable witness who clearly exaggerated her symptoms and impairments.

[14] Even if ingesting the delimer solution caused the Plaintiff some short-lived and minor injury, any damages that flow from the incident should be de minimis.

The “But For” Test

[15] In Canadian tort law, the “but for” test is used to determine causation: see Athey v. Leonati, [1996] 3 S.C.R. 458. It is a factual inquiry. A plaintiff must demonstrate that “but for” the negligent act or omission of the defendant, the plaintiff would not have suffered the injury or loss complained of. In other words, to establish liability, a plaintiff must satisfy the court that the defendant’s negligence was necessary to bring about the harm suffered.

[16] Causation need not be determined by scientific precision: Athey, at para. 16, citing Snell v. Farrell, [1990] 2 S.C.R. 311, at p. 328. The “but for” test must be applied using a robust common-sense approach to evidence. The court is permitted to draw inferences from the body of evidence before it to arrive at the conclusion that the defendant’s negligence probably caused the loss. It follows that there is no obligation upon a plaintiff to establish that a defendant’s negligence is the sole cause of the injury. The presence of other tortious or non-tortious contributing causes does not reduce the defendant’s liability.

The Plaintiff – Direct Evidence

[17] The Plaintiff was born on November 4, 1987. She was diagnosed with ADHD in Grade 1. She was sexually abused as an adolescent. She experimented with drugs and alcohol in high school. She dropped out of high school in 2005 but returned in 2010 and achieved her Grade 12 equivalent.

[18] In the years preceding the MVA, she was employed at various positions, including at Tim Hortons, on an assembly line, at her mother’s salon, at a nursing home, in retail at Payless shoes, in administration at Sundial Inn, and in snow removal, grounds care, and gardening.

[19] The MVA caused the Plaintiff neck and back injuries, which in turn led to headaches, whole body pain, difficulty walking, and tingling in the hands. She suffered psychological sequelae featuring nightmares and flashbacks. Those problems went on to become permanent.

[20] Following the settlement of her MVA claim in 2013, the Plaintiff remained off work until 2015. She found employment with Nordia in May 2015. The CSR position was not physically demanding. She enjoyed the work and experienced no difficulty talking on the telephone for long hours. She hoped to thrive and progress within the company. She earned minimum wage but was eligible for commissions and bonuses. The position offered extended health care coverage. The Plaintiff earned $14,452 from this employment from May until December 1, 2015.

[21] The Plaintiff described the incident as occurring on a normal workday. She attended at the McDonald’s drive-thru in the company of her work colleague, Samantha Smith. The Plaintiff ordered a “triple triple” large coffee with a shot of pumpkin spice. There appeared to be nothing unusual about the cup when it was delivered to her at the drive-thru window. Moments later, the Plaintiff removed the drinking tab and swallowed down a large gulp of the liquid inside.

[22] The Plaintiff immediately noticed something was wrong with the beverage. It was the foulest thing she had ever tasted. She looked inside the cup and noticed a mix of orange liquid with little white chunks floating in it. She assumed it to be curdled cream. She returned to the drive-thru to exchange the coffee. An employee explained that the beverage contained descaling liquid, which had been used to clean the coffee pots. She was issued a replacement coffee with a free ice cream and returned to work.

[23] Twenty to thirty minutes later, the Plaintiff noticed a tingling sensation in her mouth. She suddenly felt weak and nauseous. She vomited into a garbage can. She then experienced a terrible chill and became violently ill. She pushed through to finish her shift. She called poison control and was told to inquire with McDonald’s about the name of the descaling product. Poison control advised that the product might have been similar to “CLR”, a calcium, lime, and rust remover product. Poison control recommended that she attend the hospital. She felt weak and lethargic from vomiting. She attended the Orillia Soldiers’ Memorial Hospital (“OSMH”) at approximately 9:50 p.m. that same evening.

[24] Over the following days, the Plaintiff felt bumps and noticed a foul taste in her mouth. She experienced diarrhea, was still in pain, and continued to vomit. She returned to OSMH, where she was advised to rest her voice and to consume only soft food and water.

[25] The Plaintiff consulted briefly with her new family doctor. She then met with a nurse practitioner, Janelle Wilson, who suggested an endoscopy. She was referred to Dr. Riordon and to Dr. Slivko. A few months later, she was assessed by an ears, nose, and throat (“ENT”) specialist, Dr. Wong. Dr. Wong performed an endoscopy and recommended vocal rest, soft food, a prescription of Gabapentin, and an assessment by a speech-language pathologist.

[26] The Plaintiff attempted to return to her CSR position a few weeks after the incident. She managed to tolerate only 20 hours per week. There were no modified duties available. She remained with Nordia until December 18, 2015, when she opted to go on sick leave.

[27] The Plaintiff listed her present physical complaints as follows:

• Daily variable throat pain
• Throat pain exacerbated by swallowing, drinking, chewing, ingesting solid food, and talking
• Nausea
• Raspy/hoarse voice

[28] The pain has not improved over time. At times it is unbearable. It affects every aspect of her life. Sometimes, she has the sensation of breathing razor blades. She does not sing for enjoyment as she once did. She feels robbed of her identity.

[29] The Plaintiff has not returned to any employment since leaving Nordia in December 2015. She does not believe herself to be reliable. She is unable to predict the level of pain she will experience in a given day. Her MVA-related impairments still leave her unable to engage in physical work. She currently receives an income from the Ontario Disability Support Program (“ODSP”).

The Plaintiff – Cross-examination

[30] The Plaintiff claimed that her MVA-related impairments of anxiety and depression had resolved by November 2013. This coincided with the settlement of her MVA claim. However, she was continuing to report deficits in memory, concentration, and attention, as well as chronic pain and chronic depression interfering with activities of daily living, as late as August 2013. After the resolution of her MVA claim, she did not undergo any chiropractic, physiotherapy, or psychological treatment.

[31] Experts retained on her behalf for the MVA claim had deemed her to be suffering from serious and permanent impairments.

[32] The Plaintiff has been smoking since she was a teenager. Formerly a pack-a-day smoker, she now smokes only half a pack. All her medical doctors have recommended that she quit smoking.

[33] In June 2010, the Plaintiff attended the hospital complaining of abdominal pain and vomiting. In December 2012, she complained of cramping, nausea, and vomiting. In May 2014, she was complaining of constant pain in her abdomen, describing a sensation of “a fork to the intestines”.

[34] A closer examination of her employment history revealed a five-week stint in 2007 at Superior Cleaning, where she was dismissed within the probation period; Payless Shoes for three weeks in 2007, after which she was dismissed within the probation period; Travel Lodge for four months in 2007, after which she resigned because of transportation issues; and an eight-week term at Sunshine Grounds Care in the fall of 2007, after which she was laid off. She then engaged in some winter snow removal until her January 2009 MVA.

[35] The Plaintiff has a history of cocaine abuse. She first explained it as a remedy for her incident-related throat pain; but after being shown sworn evidence from her discovery, she confessed to using cocaine as far back as 2005.

[36] After ingesting the delimer solution on the day of the incident, she did not initially feel or detect any burns, blisters, or swelling upon her return to work. At no time did she look into her mouth to view what was there, even though she claims to have “felt” the burns, blisters, and swelling.

[37] Within a few weeks of the incident, the Plaintiff received information from “Lori” at McDonald’s that the product she had ingested was Kay Delimer. The Material Safety Data Sheet (“MSDS”) applicable to Kay Delimer stated that no health injury was expected from ingestion of the product under normal use.

[38] The Plaintiff was referred to Dr. Slivko, who was advised that she had sustained “chemical burns to the esophagus”.

[39] Dr. Wong recommended a course of voice therapy. The Plaintiff participated in only two sessions. She did not explore whether funding was available for continued therapy.

[40] The Plaintiff neglected to share the Kay Delimer MSDS detail with any of her treating medical practitioners.

[41] The Plaintiff was presented with a note from her dietitian, who suggested that she was eating a lot of fast food, that she was eating out three times per week, and that she enjoyed bagels from Tim Hortons and Wendy’s “baconators”. She explained that she told the dietician that she only “craved” fast food and attempted to clarify that she could not eat these foods like a normal person.

Discussion

MTD and Throat Injuries

[42] For the reasons which follow, I am not persuaded that the Plaintiff sustained any chemical or caustic injury to her throat because of the incident. At most, she experienced an unexpected, unpleasant, but transient sensation in her mouth when she gulped down the delimer solution served to her at the McDonald’s drive-thru. This may have been accompanied by some upset in the stomach, some nausea, and a bout of diarrhea. I am certainly not persuaded that the incident has been a “but for” cause of her MTD, ongoing throat pain, voice hoarseness, and difficulty with swallowing, which she continues to report to this day.

The Plaintiff’s Credibility

[43] I reject a great deal of the Plaintiff’s evidence. I did not find her to be credible. She was clearly exaggerating her symptoms related to the incident while noticeably downplaying the role played by her pre-existing condition, the long-term impact of the MVA, her psychological make-up, longtime smoking, and cocaine abuse. I find it troubling that she would testify that she had essentially recovered from her psychological and emotional difficulties by 2013. The evidence from her “experts” retained for the MVA claim described her psychological condition as serious and permanent, leaving her with few vocational options. The Plaintiff’s testimony about pre-incident improvement in her condition fits far too comfortably into a theory of the case which seeks to establish her pre-incident earning capacity as narrow but solid. It was obvious that this was an attempt to lay the groundwork for a future income loss award. The suggestion that she experienced this “recovery” in 2013 after the resolution of her MVA claim runs counter to the evidence from her own experts in 2013. The fact that this sudden and unexpected improvement from a permanent and career-altering condition spontaneously occurred in the two-year window between the resolution of her MVA claim and the incident is completely unsupported by any medical or expert evidence. I find it implausible that such a remarkable recovery could have been achieved without the assistance or benefit of therapy.

[44] The Plaintiff’s insistence that she had blisters in her mouth as a result of ingesting the delimer solution serves to damage her credibility. Not only did the Plaintiff not actually discover blisters inside her mouth, but neither did any third party, including the OSMH staff or any of the treating doctors, who would surely have discovered and noted them during an examination. I find that her insistence on the presence of blisters in her mouth was a conscious attempt to “sell” the notion that the physical trauma from the incident was detectable and significant, thus laying a basis for inferences to be drawn that her MTD and ongoing symptomatology were related to the incident.

[45] The Plaintiff reported to Dr. Werger that she was “spitting up blood”. This was several years after the incident. Nowhere in the record of any treating medical health care professional, most of whom saw her within six months of the incident, is there a reference to such a thing. This was undoubtedly an overstatement of her symptoms, which I find is consistent with her approach to the claim: to exaggerate her physical symptoms, link those symptoms uniquely to the incident, magnify the severity of the injuries and thus increase the value of her claim.

[46] I find that, had her voice issues been so serious as to prevent her from returning to her previous employment, she would have diligently pursued the recommended voice therapy and, in doing so, investigated OHIP-funded or community-based services. There is simply no evidence that she did. This is not to be mistaken as a finding of failure to mitigate. That would require some positive evidence on the part of the Defendant. Rather, the contemporaneous and abject lack of motivation demonstrated by the Plaintiff to improve her condition serves as evidence that her reported symptoms were either not genuine or not as serious as reported.

[47] Dr. Adrienne Wong, whose evidence will be considered more closely below, examined and assessed the Plaintiff on October 28, 2016 and January 11, 2017. According to entries in the clinical chart, the Plaintiff had advised Dr. Wong that she was “not working because working part-time is less than being on a disability” and that she had not returned to work because she received more from ODSP than working part-time. The Plaintiff first denied reporting this and then suggested that it had been taken out of context. But Dr. Wong confirmed that these were contemporaneous and accurate notes. I find those entries to be independent, contemporaneous, and highly reliable records which shed considerable light on the Plaintiff’s mindset and motivation at the time of her seeking treatment. I also find them to be highly damaging to the credibility of the Plaintiff and the validity of her damages claim.

Lay Evidence

[48] The lay evidence called by the Plaintiff featured longtime friend Shauna Lopes, who testified to noticing the Plaintiff with a raspy voice and complaining of pain and difficulty eating and talking after her throat injury. Shauna Lopes described the Plaintiff as a former social butterfly who is now depressed, avoids social outings, and lives essentially like a hermit.

[49] I can give little weight to this evidence. The witness was clearly exaggerating, painting the Plaintiff’s world more bleakly than the Plaintiff did herself. I noted how this witness steered entirely clear of discussing any of the MVA-related impairments present at the time of the incident. Having known the Plaintiff for more than 20 years, Ms. Lopes should have been well placed to provide a snapshot of her friend’s complaints left over from an MVA, which left her with serious and permanent sequelae (see below evidence of Allan Walton and Dr. Miller). The evidence of Ms. Lopes struck me as rehearsed, contrived, unrealistic, and not worthy of belief. I give it no weight.

[50] The Plaintiff’s sister, Erin MacNeill, at least acknowledged the Plaintiff’s pre-existing limitations in the labour market. That said, this witness has resided in British Columbia for much of her adult life and could add little to the post-incident narrative other than the recollection that the Plaintiff’s voice sounded hoarse and scrabbly on the telephone. This evidence weighs little on the issue of causation and does not serve to enhance the Plaintiff’s credibility.

[51] Lindsay Ellsworth was the Plaintiff’s supervisor at Nordia. While she was able to attest to the Plaintiff’s alleged struggles to return to a position that was demanding on the voice, I find that she too was misled by the Plaintiff, who misinformed her that she had “scarring on the throat”. Ms. Ellsworth had no opportunity to verify that the Plaintiff had objective injuries and no means by which to confirm that her complaints were genuine. Moreover, Ms. Ellsworth has not spoken to the Plaintiff since 2015 and therefore has been unable to monitor her condition or recovery. This witness took the Plaintiff at her word. Her evidence is only as good as the source that she obtained it from. I can give it little weight.

Orillia Hospital Records

[52] The OSMH records reveal no evidence of mucosal injury. No swelling, redness, blisters, or bleeding were noted or found by the hospital staff on the evening of the incident. Nothing of significance prompted emergency personnel to call in a specialist or to recommend to the Plaintiff that she obtain a referral to one.

Post-OSMH

[53] The Plaintiff first reported her symptoms to nurse practitioner Janelle Wilson on October 15, 2015, where she reported a chemical burn to the esophagus. She returned on October 22, 2015, complaining of a hoarse voice, throat pain, and difficulty speaking. However, upon examination, Ms. Wilson found no burns, swelling, or redness in the areas complained of.

[54] Ms. Wilson referred the Plaintiff to Dr. Riordon for a scope. The Plaintiff returned on November 27, 2015, complaining of nausea, vomiting, voice fading, and throat pain with overuse. The scope performed by Dr. Riordon had shown only mild reflux esophagitis. On December 3, 2015, the Plaintiff requested a leave of absence from work to allow for her voice to recover. Following an assessment of hoarse voice and throat pain, Ms. Wilson had the impression that the Plaintiff had dysphagia. She provided the Plaintiff with a note to take an 8-week absence from work and made a referral to ENT specialist Dr. Wong. Ms. Wilson last saw the Plaintiff in April 2016.

Dr. Slivko

[55] The Plaintiff saw Dr. Slivko on referral. Although Dr. Slivko was advised that the Plaintiff had sustained “chemical burns to the esophagus”, there is no basis for that referring diagnosis. Indeed, the origin of that description of the Plaintiff’s injury is unclear. It most certainly would not have emerged from any objective findings at the OSMH. That said, any medical assessor charged with reviewing the Plaintiff’s situation and possessed of the notion that she had sustained “chemical burns” might naturally ascribe any throat conditions she complained of to the incident. This might distort, perhaps irreparably, their respective views of causation to the extent they felt inclined to comment on it. We will see below how Dr. Korman was misinformed about the chemical composition of the delimer solution that the Plaintiff ingested.

Biochemical Evidence

[56] There was no biochemical expert opinion that the delimer solution ingested by the Plaintiff could have caused the injuries as alleged.

[57] Christopher Ciasnocha was qualified as an expert in chemical exposure and occurrences. Following a ruling from the court, his opinion was limited to formulating and expressing the likely level of pH of the delimer solution ingested by the Plaintiff. He arrived at a pH level of between 2.5 and 3.1 based on the evidence provided by the McDonald’s employees and on the MSDS of the Kay Delimer product. He also admitted that the combined effect of cream being added to the coffee, the chemical reaction between the citric acid in the solution and the limescale build-up inside the coffee machine, likely resulted in the pH of the solution ultimately ingested being less acidic than his calculated range.

[58] Mr. Ciasnocha also testified that the pH of citric acid, which is on the list of permitted food additives by Health Canada, is usually between 3 and 6. Lemon juice, which is made of citric acid like that found in the delimer solution has a pH level of between 3 and 6.

[59] This means that the Plaintiff ingested a volume of liquid with an acidic content similar to and quite possibly lower than lemon juice. This aligns with the information provided on the MSDS that, even with ingestion of Kay Delimer, “health injuries are not known or expected under normal use”. In addition, as of 2014, the Workplace Hazardous Materials Information System (“WHMIS”) provides the product with a rating of “1” or “slight” under the category “health”.

[60] I would assign no weight to the portion of Mr. Ciasnocha’s testimony opining on the likely effects of ingesting “Lime A-Way”. This is an entirely different product than the Kay Delimer product used by McDonald’s. Unlike the Kay Delimer, Lime-A-Way contains phosphoric acid and nitric acid. As admitted on cross-examination, the ingredient in Kay Delimer, citric acid, is not only a weak acid but is a permitted food additive. Lime-A-Way is distinct from Kay Delimer precisely because the nitric and phosphoric acids found in the former are more potent. Indeed, it is not surprising that the WHMIS classification for Lime-A-Way under the “health” category is a 3, which denotes “high”. But the Plaintiff did not ingest Lime-A-Way or anything close to it.

Dr. Wong – ENT

[61] Dr. Adrienne Wong was the Plaintiff’s treating ENT. She was not qualified as an expert under Rule 53 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194. She was therefore not permitted to provide an admissible opinion on the effects of the delimer solution on the Plaintiff (i.e., causation) or on the Plaintiff’s prognosis.

[62] The Plaintiff came to her complaining of throat pain exacerbated by prolonged talking.

[63] Although Dr. Wong diagnosed and treated the Plaintiff for MTD within a few months of the incident, she found no indication of any blistering, scarring, or redness in the Plaintiff’s oral cavity. The only pathological finding was the presence of nodules. These develop over time and form like calluses on the vocal folds. They are unlikely to be present from a “spontaneous event” (i.e., a trauma).

[64] Dr. Wong explained that MTD is similar to muscle tension and soreness after overworking muscles in the gym: muscles around the larynx become tense, inflamed, and painful leading to pain and lack of voice control.

[65] Dr. Wong acknowledged that MTD has many causes. She conceded that stomach acid content from repeated vomiting over a number of years is likely higher than the acidic content of the delimer solution ingested on one occasion. She also conceded that MTD can develop from acid reflux/gastroesophageal reflux, cigarette smoking, and heavy voice use.

[66] Dr. Wong believed that the Plaintiff had ingested a “caustic substance” but had no details about the pH level or acidic make up of the delimer solution that was consumed.

[67] By August 12, 2016, less than one-year post-incident, the Plaintiff reported to Dr. Wong that her voice was better. Dr. Wong noted that her voice sounded more consistent and smoother. Dr. Wong interpreted this to mean that the Plaintiff was trending towards improvement. This serves to contradict the evidence of the Plaintiff, who testified at trial that she had experienced no improvement in her condition.

[68] Dr. Wong did not see the Plaintiff at all between January 11, 2017, and February 2024. By then, the Plaintiff was complaining of bilateral ear pain. In three clinic visits in February, April, and June 2024, the Plaintiff did not mention any throat or voice issues. Dr. Wong summarized that there was nothing “clinically applicable” in those visits. There has been no request for follow-up on voice and throat issues since 2017. One would have thought that if the Plaintiff continued to suffer from ongoing throat and voice problems related to the incident, she would have discussed those with the ENT specialist who was familiar and sympathetic with her condition.

[69] Dr. Wong’s “opinion” was largely based on what was reported by the Plaintiff. She could in any event provide no qualified opinion that the incident of October 1, 2015 was a materially contributing cause of the Plaintiff’s MTD. I give her testimony only limited weight.

Dr. Korman

[70] Dr. Mark Korman was qualified as an expert otolaryngologist (ENT). His original report from 2021 was inherently flawed: he based his opinion on the fact that the Kay Delimer ingested by the Plaintiff contained hydrochloric acid.

[71] Clearly it did not.

[72] And while his 2024 addendum report corrected the composition of the Kay Delimer solution, Dr. Korman deferred to the biochemical experts on the question of whether the delimer solution was sufficiently caustic to have caused a mucosal injury. That said, Dr. Korman agreed that daily vomiting over nine years (as reported by the Plaintiff) would expose the esophageal tract to repeated volumes of gastric acid, which has a pH range as high as 3.5. Dr. Korman agreed that among the primary contributing factors to MTD are heavy voice use, acid reflux, and cigarette smoking.

[73] At the time of forming his original opinion, Dr. Korman was under the misapprehension that the Plaintiff had blisters in her mouth after the incident. The evidence does not establish this. And since he opined that the presence of blisters would be a significant and objective indication of acidic trauma to the oral cavity, I can only infer that the absence of blisters would be a significant and objective indication that no trauma or very little trauma had occurred.

[74] Ultimately, Dr. Korman’s causation opinion amounts to a suggestion that a common-sense inference should be drawn. The Plaintiff did not have any issues, indications, or pain in the throat prior to the subject incident. The referrals to the treating specialists and Dr Wong’s working diagnosis of MTD both post-date the incident. It therefore follows that the Plaintiff’s condition must have been caused by a mucosal injury suffered in the incident.

[75] But that is a complacent opinion. Not only does it minimize the complete absence of documented findings of insult or organic pathology at OSMH, but it also ignores the possibility that the history of subjective complaints might have pre-dated the incident but remained unreported. The opinion also: fails to acknowledge the possibility that the subjective complaints were overstated or not genuine; overlooks the expert’s concession that he would defer to a biochemist for a causation opinion; and minimizes the impacts of other contributing factors to MTD (which he agreed would include heavy voice use, acid reflux, and smoking).

[76] Finally, Dr. Korman was not qualified to give an opinion on the impact of MTD on the Plaintiff’s vocational abilities and options.

[77] Dr. Korman’s opinion, to the extent I accept it, did not support the position of the Plaintiff on causation or damages. His opinion was largely based on temporal considerations rather than on medical and scientific ones. I prefer the opinion of Dr. Werger, as outlined below.

Dr. Werger

[78] Dr. Jeffrey Werger was qualified as an expert in otolaryngology with experience in caustic injuries. His evidence was compelling, fair, balanced, and informative. He freely agreed with the diagnosis of MTD but emphasized how the Kay Delimer was classified as posing “no known or expected health risk” to those who ingest it.

[79] Unlike Dr. Korman, Dr. Werger was not misinformed about the content or potency of the delimer used by McDonald’s.

[80] Dr. Werger thought it important that the emergency doctors at OSMH did not discover any burns or redness in the Plaintiff’s throat on the evening of the incident. Dr. Werger reviewed the findings of gastroenterologist Dr. Riordon, who administered a scope and detected mere inflammation related to acid leaking from the stomach with mild gastritis.

[81] Dr. Werger reviewed Dr. Wong’s endoscopic examination and her clinical diagnosis of MTD following a caustic injury; however, Dr Werger pointed out that there was no suggestion of an insult or caustic burning to the mucosal tissues in the months following the incident.

[82] Dr Werger explained the significance of glottal gaps and nodules found by Dr. Korman. Dr. Werger explained how these form over a period of months or years and are brought on by voice overuse or misuse (e.g., yelling or screaming). They may explain hoarseness and a breathy voice, but both are amenable to treatment.

[83] Dr. Werger interviewed and examined the Plaintiff in June 2023. She reported “spitting up blood” and listed her complaints as raspy voice, pain with talking, daily vomiting, abnormal eating, and sensation of razor blades with breathing.

[84] Dr. Werger’s examination revealed no abnormalities – no nodules, redness, swelling, or glottal gaps, and most importantly, no evidence of scarring or previous throat injury.

[85] Dr. Werger emphasized that common causes of MTD include acid reflux, voice abuse, and smoking.

Acid Reflux/Gastroesophageal Reflux Disease (“ARGRD”)

[86] According to Dr. Werger, the Plaintiff suffers from ARGRD. While there was general agreement that this affliction may be a contributing cause of the MTD, there was simply no evidence that the ARGRD can be attributed to the incident. Neither Dr. Korman nor any other medical professional testified that the approximately two ounces of the delimer solution ingested by the Plaintiff in the incident could have caused the Plaintiff to develop ARGRD.

Conclusion on Causation of MTD

[87] While I accept that the Plaintiff may continue to suffer from MTD, I find that the Plaintiff has failed to prove on a balance of probabilities that “but for” the trauma she sustained from the incident, she would not have the MTD condition. It is just as plausible that the acid reflux from vomiting hundreds (perhaps thousands) of times, combined with heavy voice use and the negative effects of smoking, has caused the MTD. The scientific and non-scientific evidence, either treated separately or taken together, is insufficient to discharge the Plaintiff’s burden to prove on a balance of probabilities that her condition is causally related to the incident.

Psychological Injuries and Vocational Status

[88] I am unable to find that the Plaintiff suffers from any compensable psychological or emotional conditions or symptoms that relate to the incident.

Dr. Miller and Allan Walton

[89] I reject the evidence of the twin psychological and psychovocational experts called by the Plaintiff. Dr. Philip Miller and Allan Walton of Fox Psychological Services co-authored a report dated December 3, 2021 (the “2021 report”), which purported to offer both a psychological opinion and an opinion on the Plaintiff’s vocational abilities, impairments, and employability.

[90] Quite astonishingly, these two Rule 53 qualified experts omitted to mention, in either the 2021 report or their direct examination, that their clinic had previously assessed, diagnosed, and delivered a litigation report for the Plaintiff dated September 9, 2013, in respect of her 2009 MVA (the “MVA report”). In the MVA report, the diagnosis arrived at by these experts was that the Plaintiff suffered from a serious and permanent psychological impairment characterized by a vicious cycle of pain and isolation. The opinion went on to conclude that the Plaintiff was completely unable to return to her previous occupations. From a psychovocational perspective, these experts could not identify a suitable occupation for the Plaintiff; they deemed her to be “basically unemployable”.

[91] Failing to reference the MVA report in either the 2021 report or their respective direct evidence constitutes a serious omission. This omission greatly undermines both the credibility of these two experts and the reliability of their respective opinions. This is not a case where the opinions offered in the MVA report were equivocal or irrelevant. They were emphatic opinions and were crucial to an understanding of the Plaintiff’s pre-existing conditions, impairments, limitations, and vocational options at the time of the incident.

[92] Both Mr. Walton and Dr. Miller concluded that the Plaintiff met the diagnostic criteria for the following conditions: major depressive disorder with anxious distress, moderate to severe; and somatic symptom disorder with predominant pain, persistent moderate severity. And while both experts conceded that these conditions resulted from a combination of the Plaintiff’s childhood, the MVA, and the incident, both their reports and their examinations-in-chief skirted the fact that Dr. Miller had rendered a diagnosis in 2013, which, if not identical to that given in the 2021 report and at trial, was strikingly similar: pain disorder associated with psychological factors and a general medical condition, adjustment disorder with mixed anxiety and depressed mood, and post-traumatic stress disorder. Indeed, both experts recognized that, in preparing their 2021 report, reference could and should have been made to the MVA report and its conclusions. At the very least, it would have been helpful to compare the 2013 diagnoses with those from 2021.

[93] The failure of these two experts to inform the court both in the 2021 report and in their respective examinations-in-chief that they had prepared a report for the MVA-related impairments back in 2013, which found the Plaintiff to be suffering from significant psychological impairments and vocational limitations two years before the incident, cannot be overlooked. I find that it constitutes a breach of their respective duties as experts to provide the court with opinion evidence that is fair, objective, and non-partisan.

[94] The two “opinions”, considered in tandem, raise other troubling questions. In the MVA report, Mr. Walton found the Plaintiff to be significantly limited in her vocational choices moving forward and likely unable to find work. Assuming that opinion was accurate when given, it runs counter to the fact that the Plaintiff returned to full-time employment at Nordia in May 2015 (and began looking for work in 2014), that she apparently required no vocational supports or accommodations, that she required no time off work until after the incident, and that she did not appear to require ongoing treatment for the serious psychological condition from which she apparently suffered.

[95] This history suggests that the Plaintiff achieved a remarkable recovery after November 2013, an outcome that was clearly not contemplated in the MVA report. While a recovery from her 2013 status was certainly possible, and to be applauded if achieved, one is left with the impression that the conclusions in the MVA report are wholly incompatible with the notion that any of her current problems were caused or contributed to by the incident. I seriously doubt both the credibility of these experts and the reliability of any opinion they have offered on the Plaintiff’s psychological condition, its origins, severity, and the impact it has and will have on her vocational options.

[96] I am not prepared to afford the companion opinions of Mr. Walton and Dr. Miller any weight. Not only do I find them to be fatally compromised by their lack of impartiality, but by their own admission, it was important for them to differentiate between the pre-existing psychological conditions from the 2009 MVA and any new developments from the incident in question. That differentiation would be highly relevant since it would have provided a baseline to compare the Plaintiff’s prior psychological status and the impairments she attributes to the incident. Without that “expert” opinion and comparison, from two individuals well placed to provide it, their twin opinions are of little utility to the court.

Dr. Mor

[97] In contrast, Dr. Shulamit Mor conducted a single psychovocational assessment of the Plaintiff. I found her opinion focused, straightforward and impartial. She was unable to diagnose the Plaintiff with any psychological disorders. The Plaintiff demonstrated some somatization, which is a preoccupation with physical symptoms. Nonetheless, she found the Plaintiff to be coping reasonably well. Moreover, Dr. Mor concluded that any chronic pain that the Plaintiff was suffering from was a result of the 2009 MVA.

[98] I accept the opinion of Dr. Mor. It was untainted by the problems plaguing the twin opinions of Mr. Walton and Dr. Miller. Moreover, assigning the Plaintiff’s chronic pain to the 2009 MVA was consistent with the preponderance of the evidence, including the opinion offered by physiatry specialist Dr. Ko in 2013. Indeed, Dr. Miller relied on that opinion to ascribe a chronic pain condition to the Plaintiff’s list of impairments arising out of the 2009 MVA.

[99] On balance, other than some temporary upset and uncertainty, I am not persuaded that the Plaintiff sustained or developed any psychological impairments or conditions because of the incident. The Plaintiff has not discharged her onus of proving that but for the incident, she would not suffer from any of her ongoing psychological and emotional conditions.

Spoliation

[100] The Plaintiff raised the issue of spoliation of evidence. She alleges that the Defendant should not benefit from the Plaintiff’s inability to make use of the evidence that the Defendant failed to preserve. The Plaintiff contends that the actual contents of the delimer solution partially consumed on the date of the incident, the precise delimer product used to clean the coffee vats, the Defendant’s internal incident report, and the video clip of the drive-thru exchange were unavailable to her. This compelled the Plaintiff’s expert to conduct his inspection of a liquid-based delimer produced by Ecolab as an exemplar of the powder-based Kay delimer used by McDonald’s. The Plaintiff asks that I draw a series of adverse inferences as a result of the spoliation of evidence.

[101] I decline to draw any adverse inferences against the Defendant.

[102] One, it was not unreasonable in the circumstances for McDonald’s staff to discard the contents of the coffee cup. The evidence suggests that the Plaintiff returned to the drive-thru in good spirits, accepted her replacement coffee and free ice cream, and did not complain of anything other than the beverage having a foul taste. McDonald’s could not have reasonably predicted any injury or foreseen litigation arising from this obscure and benign incident.

[103] Two, asserting privilege over an incident report does not amount to spoliation. If the Plaintiff had wished to challenge the claim for privilege, she ought to have done so by way of an interlocutory motion. There is no evidence that the report was destroyed. I am not prepared to make an adverse finding against the Defendant if the Plaintiff did not think it important enough to challenge the claim for litigation privilege by way of an interlocutory motion long before trial.

[104] Three, there is no evidence that the items in question were intentionally destroyed with the intention of manipulating or limiting the record available for trial.

[105] Four, in respect of the CCTV security footage of the drive-thru, I cannot see how the evidence would be relevant to any issue. There is no dispute about how, when, or where the Plaintiff purchased the product. It is not denied that the product contained a quantity of deliming agent, that the Plaintiff returned the product almost immediately, that the product was promptly replaced, and that the original product was discarded. The CCTV footage would not add to or subtract from those facts. Moreover, the CCTV cameras are focused on the area of the cash registers, not on the area where the coffee vats were cleaned.

[106] Five, McDonald’s responded to the Plaintiff’s formal complaint by furnishing her with the MSDS for the Kay Delimer in the immediate aftermath of the incident. By the time the request was made from Ecolab for the actual Kay Delimer used by McDonald’s at the time of the incident, the product was no longer available. The Defendant cannot be blamed for that.

[107] Finally, the drawing of an adverse inference is discretionary: see Liquid Capital Exchange Corp. v. Daoust, 2024 ONCA 489, para 39. The facts of this case do not weigh in favour of drawing an adverse inference against McDonald’s.

Damages

General Damages

[108] I would not assess the Plaintiff’s damages at any more than a token amount.

[109] No doubt, the experience of tasting something foul in the coffee cup, followed by the discovery that she had ingested a quantity of delimer solution, was temporarily unsettling for the Plaintiff. It likely caused her a bout of nausea and perhaps even diarrhea or vomiting to void the product from her body. It understandably led to a brief period of anxiety and uncertainty, which led her to contact poison control and to attend at the hospital that evening and again several days later.

[110] That said, the evidence fails to establish that she suffered any serious, complicated, or permanent injury to her throat or oral cavity.

[111] I am not persuaded that her present complaints, even if they are genuine, are causally linked in any way to the incident of October 1, 2015.

[112] Beyond a matter of hours, any pain in her throat or oral cavity and any disruption in her voice quality caused by the ingestion of the delimer solution would have subsided.

[113] And since the physical/pathological symptoms that she described cannot be causally linked to the incident, nor can any psychological or emotional problems or any exacerbation of her premorbid conditions be tied to the incident.

[114] In light of my findings, I would assess general damages for temporary pain, suffering, and inconvenience at $5,000.

Loss of Income

i) Past Loss of Income

[115] There is no basis for a past loss of income award. I am not persuaded that the Plaintiff’s condition was such that she could not continue to carry out the tasks of her employment. Whatever the impediments to her continuing in that employment, they were not related to the incident in question.

ii) Future Loss of Income

[116] I see no basis for any future loss of income claim. The Plaintiff returned to work several weeks post-incident and could have continued to work had she chosen to. Similarly, there is no loss of earning capacity or loss of competitive advantage stemming from the incident. Any impairments affecting the Plaintiff’s ability to engage in certain types of employment are related to the MVA or to other issues, either pre-existing or unrelated to the incident. The reason for the Plaintiff’s election not to return to work was made plain from the records of Dr. Wong - she earns more money on disability than if she were to return to the call centre.

iii) Future Care Costs

[117] I am not prepared to award any damages for future care, goods, or services. I am not persuaded that any of those identified or quantified by Ms. Tennen are reasonable or necessary as a result of any injury sustained in the incident. There is no real and substantial possibility that those costs for goods and services will be incurred by the Plaintiff. Not only does the Plaintiff’s condition related to the incident not warrant an award under this heading, but in the period since the incident, the Plaintiff has demonstrated that when services have been recommended to her (such as voice therapy, pain management, and physiotherapy), she has either failed to meaningfully participate in them or to reasonably explore opportunities for third party funding (e.g., OHIP and the Community Care Access Centre). Any award for future medical and health care and related goods and services would be entirely unnecessary and unwarranted.

Summary and Disposition

[118] The Plaintiff has failed to establish that her MTD and related physical complaints are causally related to the incident of October 1, 2015.

[119] The Plaintiff has failed to establish that any of her current psychological or emotional complaints are causally linked to the incident.

[120] The Plaintiff has failed to establish entitlement to an award of past or future loss of income, future loss of earning capacity, or future care costs.

[121] The Plaintiff shall have judgment for the sum of $5,000 for general damages, plus applicable pre-judgment interest from the date of the incident.

[122] Exhibit 39 at trial was an OHIP subrogated claim summary. Neither party made submissions on this issue. The parties may agree on the amount of the subrogated claim to be allowed and include it in any proposed draft judgment. Alternatively, they may address that outstanding issue at the appearance on costs/pre-judgment interest and make submissions at that time.

[123] Should the parties be unable to agree upon the issues of pre-judgment interest or costs, they may take out an appointment to appear before me to address these issues through the Trial Coordinator at Barrie.

Sean McCarthy

Released: June 24, 2025