Court File and Parties
CITATION: Wallis. v. Wawanesa Mutual Insurance Company, 2026 ONSC 2636
COURT FILE NO.: CV 18-00002594-0000
DATE: 20260504
SUPERIOR COURT OF JUSTICE – ONTARIO
RE: Linda Wallis, Plaintiff
AND
John/Jane Doe, Jack/Jill Doe and The Wawanesa Mutual Insurance Company, Defendants
BEFORE: Justice Spencer Nicholson
COUNSEL: Karl Arvai for the Plaintiff Laura Emmett and Emily Rasic for the Defendants
HEARD: April 29, 2026
MID TRIAL RULING RE EXPERT WITNESS
NICHOLSON J.:
[1] This is a lengthy jury trial arising out of a motor vehicle accident dated December 22, 2016, in which the plaintiff, Linda Wallis, is alleged to have sustained serious injuries when her motor vehicle was struck from behind by an unidentified driver.
[2] The trial commenced on March 30, 2026, and is about to enter its sixth week.
[3] This Ruling should be read in conjunction with my Mid Trial Ruling dated April 22, 2026, (Wallis v. Wawanesa Mutual Insurance Company, 2026 ONSC 2423). In that Ruling, I held that Dr. McDermid, the plaintiff’s treating psychologist of 9 years could give evidence as both a participant expert witness and a litigation expert witness who had effectively complied with Rule 53.03 by the delivery of three reports. It was my view that, although individually the reports did not all strictly comply with the requirements of Rule 53.03, any deficiencies in one report was cured by the other reports. The defendant had had ample notice of her proposed opinion evidence, and their experts had had an opportunity to respond to her opinions.
[4] I also expressed concern that the defendant had not raised an objection to the number of litigation expert witnesses that the plaintiff was calling until it was too late for the plaintiff to select which psychologist to call as an expert.
[5] In addition to her clinical notes and records that were prepared in the ordinary course of treating Ms. Wallis, Dr. McDermid prepared three reports for the purpose of giving opinion evidence outside the scope of a participant expert witness. These were dated March 2, 2018, February 20, 2025, and February 6, 2026.
[6] As I noted in my earlier Ruling, while the March 2, 2018, report did not set out the documents that Dr. McDermid had reviewed, the February 20, 2025, report indicated that she had reviewed the two medicolegal reports prepared by experts retained by the plaintiff, as well as a “Medical Brief Index”. Although the Medical Brief Index had not been appended to the report, I ordered that plaintiff’s counsel provide that index to defense counsel, assuming that if there were no “new” documents, the defendant would not be surprised by the contents of the report.
[7] As ordered, plaintiff’s counsel produced the Medical Report Index. I was not provided a copy.
[8] I had misunderstood (and for the purpose of this decision I do not believe that I was misled in any way) what Dr. McDermid had reviewed in preparation of her February 20, 2025, report. I had assumed that she had been provided with a fulsome document brief. Accordingly, I had been under the impression that Dr. McDermid was intimately familiar with most of the medical evidence in this case at the time that she authored the February 20, 2025, and February 6, 2026, reports. I note that the bulk of her opinion evidence is contained within the February 20, 2025, report.
[9] In fact, Dr. McDermid had only read the two plaintiff medical reports and the Medical Brief Index (meaning the list of documents) but not the actual documents contained within the Index when she authored the February 20, 2025, report. She later read the Future Care Costs report prepared on behalf of the plaintiff, and the defense medicolegal report of a neuropsychologist when she prepared the February 6, 2026, report.
[10] In my previous Ruling, I described that in my view, the manner in which Dr. McDermid’s reports were authored presented as objective. I remain of the view that the reports were written in an even-handed fashion. However, my initial assessment was impacted by my erroneous belief that she had been exposed to most of, if not the entire, medical file when she wrote her February 20, 2025, report.
[11] Dr. McDermid testified before the jury with respect to her qualifications, and I accepted that she was qualified to give opinion evidence, as both a participant expert and a litigation expert who had filed Rule 53.03 compliant reports in the field of clinical, health and rehabilitation psychology. She acknowledged during that process her obligation to the court to provide evidence that is fair, objective and non-partisan. She testified in-chief, and again, it was my view during her examination-in-chief that she presented as balanced. I had no concerns.
[12] It was on Dr. McDermid’s cross-examination that it was first laid bare (at least to me) that Dr. McDermid had not, in fact, been provided with the actual Medical Brief of documents, but merely the index to such a brief. I first became aware that she did not actually read any of those documents before she prepared her February 20, 2025, report, nor request to read any of the documents during her cross-examination.
[13] As her cross-examination continued, it was discovered by defense counsel and the court, that Dr. McDermid had contacted plaintiff’s counsel’s office days before the trial commenced and obtained the family doctor’s clinical notes and records from January 2014 to January 15, 2026, for her to review before testifying.
[14] We excused the jury, and I permitted defense counsel to have overnight to consider how she wished to proceed. The next morning, Dr. McDermid reattended and, in the absence of the jury, was asked questions about how she came to request those documents, what documents she received and what she reviewed.
[15] In addition to the family doctor’s clinical notes and records, Dr. McDermid also received an Expert Reports Brief on the first day of trial. She indicated that she wanted to make sure that she had done some preparation work as part of her “due diligence” because of her duty to be fair, objective and non-partisan. She indicated that, for example, if the plaintiff was now on life support, she did not want to be caught by surprise.
[16] Defense counsel then continued to cross-examine Dr. McDermid in front of the jury, reserving what relief she might seek. I interrupted the resumed cross-examination without alerting the jury to my concerns, excused the jury and indicated to counsel that I wanted to review Bruff-Murphy and address the issue sooner rather than later.
[17] After reviewing Bruff-Murphy, I heard submissions from counsel about how to deal with the situation that had arisen. Defense counsel wanted to complete her cross-examination, I am sure for the purpose of establishing the record, and plaintiff’s counsel then completed his re-examination of Dr. McDermid.
[18] During the course of her cross-examination, Dr. McDermid was very unclear on what she had actually reviewed at any time during this litigation or the treatment of the plaintiff. It was clear that she was relying heavily on the summary of the evidence contained in the plaintiff’s two medical reports that she had read in preparing her reports. She indicated that from time to time, the plaintiff as her patient would bring reports to their treatment sessions and Dr. McDermid would review them, but return them. Thus, they were not contained within Dr. McDermid’s file. This included, for example, two medicolegal reports from a neuropsychologist retained by the plaintiff. These two reports were also contained in the brief that were forwarded to her shortly before trial. Given that the reports were authored in 2018 and 2019, she most likely reviewed them prior to writing her February 20, 2025, report. The plaintiff had also shared with her the defense physiatry report during her treatment sessions.
[19] During her cross-examination, Dr. McDermid then indicated that although she had requested and received the medical brief documents shortly before trial, she had only read some of them. She could not identify which documents. With respect to the family doctor’s records, she “can’t say what she reviewed and what she didn’t”.
[20] Her position, echoed by plaintiff’s counsel, is that she was giving a psychological opinion only, within the scope of her expertise, and thus, it was not relevant if she knew the particulars of the plaintiff’s physical health, pre-and post-accident. The problem with that argument is that Dr. McDermid offered the following comments and opinions in her reports:
• Ms. Wallis has difficulty performing many tasks and activities that she completed independently prior to the collision;
• Ms. Wallis continues to experience physical, cognitive and psychological difficulties on a daily basis that cause marked interference in her functioning;
• Following the 2016 accident, Ms. Wallis reported an exacerbation of pre-existing pain and an onset of new pain symptoms;
• Ms. Wallis has difficulty performing most day-to-day activities that she used to complete independently prior to the accident because of the combined and interactive effects of the physical, cognitive and psychological impairments;
• Ms. Wallis’ impairments have resulted in widespread life disruption and cause significant interference in multiple areas of functioning (e.g., occupational, physical, emotional, cognitive, recreational, social).
• Ms. Wallis’ physical, psychological, and cognitive impairments from the accident affect her physical and mental stamina and endurance, concentration, memory, ability to focus on a task, ability to process and organize may types of day-to-day information and generally decrease her tolerances for stress.
• Ms. Wallis is not able to return to her pre-accident occupation because of the combined and interactive effects of her pain, psychological and cognitive impairments from the accident.
• With respect to causation, Ms. Wallis did not report a significant history of pre-accident psychological difficulties.
[21] Accordingly, although Dr. McDermid indicates that she was only concerned with Ms. Wallis’ psychological status, she has commented upon and offered opinions implicating her physical impairments, both pre-and post-accident. She testified that being qualified as a rehabilitation and health specialty meant that physical impairments were within the scope of her expertise. However, as her cross-examination made clear, Dr. McDermid had practically zero understanding of Ms. Wallis’ pre-accident physical conditions and an incomplete understanding of her pre-accident psychological condition, without referring to a report prepared by another expert. I disagree with Dr. McDermid’s view that it was enough to know that Ms. Wallis was able to work before the accident and that she was unable to work after the accident.
[22] Any comparison of function pre-and post-accident requires an adequate appreciation of function both pre-and post-accident. Dr. McDermid could only focus on post-accident because she did not independently review any of the pre-accident records before writing her reports, relying on the plaintiff’s medicolegal experts’ summaries.
[23] It became clear during her cross-examination that the real source of Dr. McDermid’s understanding of Ms. Wallis’ medical condition pre-and-post accident is Ms. Wallis’ self-reports. The role of a fair, objective and non-partisan expert is not to simply parrot the plaintiff’s evidence.
[24] By way of further example, Dr. McDermid testified that she did not really know what limitations Ms. Wallis’ pre-accident carpal tunnel syndrome was affecting her pre-accident function, but that it was “in a different way than post-accident”. I agree with defense counsel that Dr. McDermid simply has no basis for that statement as she had not read all, or any, of the pre-accident records when she wrote her reports.
[25] Dr. McDermid testified forcefully in cross-examination “Ms. Wallis did not have functional limitations like she has now”. However, Dr. McDermid did not put herself in position to objectively evaluate what functional limitations Ms. Wallis had pre-accident because she did not read all, or perhaps any, of the pre-accident records.
[26] The most disqualifying aspect of Dr. McDermid’s testimony was that when it was pointed out to her what she did not know, she indicated that she had read summaries and had more than 90 treatment sessions and “had no reason to doubt that Ms. Wallis was telling me an accurate account”. Later, in re-examination, she reiterated that she did not need to go beyond the 90 sessions that she had had with Ms. Wallis over the past nine years in preparing her reports. In re-examination, Dr. McDermid indicated that reviewing the plaintiff’s physiatry expert report gave her enough perspective so there was no need to review any other records. By only relying upon reports generated by the plaintiff, Dr. McDermid was not being objective in her analysis.
[27] It is very difficult for a treating psychologist such as Dr. McDermid to separate out her concerns for the well-being of her patient from the duty owed by a litigation expert to the court. I accept that it is not impossible, but, in my view, Dr. McDermid’s evidence in this case is simply not objective. She is overly reliant on her patient’s description of pre-and post- accident conditions and did no independent review of the records to verify or question anything that Ms. Wallis told her. She made no effort to obtain any of the records in the Medical Brief Index, or any of the records that were referred to by the two plaintiff’s experts before she authored her reports.
[28] Furthermore, although I had believed that Dr. McDermid’s reports were Rule 53.03 compliant because they had disclosed what she reviewed, obviously that is not the case. The obligation of a litigation expert to provide evidence that is fair, objective and non-partisan, in my opinion, continues from the time of their retainer until the time they complete their evidence. Dr. McDermid has now reviewed without disclosing it prior to her testimony in chief a lot of records that were not reviewed by her when she authored her opinion. She cannot even articulate what she has and has not reviewed. She cannot say when she might have reviewed certain reports. She may have written her reports having only reviewed certain documentation, but by reviewing additional documents before testifying, the court is left with the impossible task of trying to determine how those subsequently reviewed documents may have impacted her testimony. It is not enough to simply say “it didn’t” because maybe, objectively, that evidence should have impacted the testimony.
[29] Given that Dr. McDermid did not, and frankly, cannot, identify what documents she has reviewed with any degree of certainty, I have concluded that she cannot be properly qualified as a Rule 53.03 expert.
[30] I wish to make clear that it is my view that Dr. McDermid was attempting to give evidence that was fair, objective and non-partisan. This is not a case of Dr. McDermid proving to be unwilling to give fair, objective and non-partisan evidence. Rather, she is unable to give such evidence because she only reviewed a fraction of the records available to her and thus, her opinion lacks the requisite objectivity. Frankly, in many ways, she was set up to fail because she was not provided with the full medical brief at the time that she was asked to provide a report outlining her opinions. Obtaining and reviewing the records just before trial was too late, especially without disclosing that further records were obtained and reviewed until cross-examination.
[31] In short, Dr. McDermid’s testimony is not of the same character as the expert in Bruff-Murphy by any means. Nonetheless, litigation experts who undertake to provide fair, objective and non-partisan evidence are assumed to have reviewed at least some of the underlying medical records. While this could have been a matter of weight, as opposed to admissibility, as noted, I am not satisfied that the court has sufficient evidence to determine what documentation Dr. McDermid has based her opinions on, and that, in my view, is fatal to her ability to testify as a litigation expert. Accordingly, the prejudicial effect of her evidence, in my view, outweighs its probative value.
Bruff-Murphy v. Gunawerdena, 2017 ONCA 502
[32] In Bruff-Murphy, the trial judge identified some initial concerns with the proposed evidence of the defense psychiatrist but nevertheless qualified him as a litigation expert and permitted him to give opinion evidence. Later, in his threshold decision, the trial judge expanded upon his concerns.
[33] The Court of Appeal made clear that the trial judge is never functus of his or her gatekeeping role with respect to expert evidence. The trial judge retains discretion to revisit the decision to admit expert evidence should concerns arise during the expert’s testimony that was not apparent when the decision was made to admit it.
[34] One of the concerns is that when a highly qualified individual, such as Dr. McDermid, is clothed with the title “litigation expert” there is a risk of her testimony being given undue weight by a jury.
[35] The Court of Appeal described the options open to the trial judge when confronted with an expert witness whose evidence needs to be addressed. Those options include a mid-trial instruction and/or an instruction in the final charge advising the jury that the expert’s witness is being excluded in whole or in part. It includes seeking instructions regarding a mistrial.
[36] At this juncture, the defendant does not seek a mistrial.
[37] The defendant did suggest both a mid-trial instruction and an instruction in the final charge. I agreed that such instruction was necessary. I also believed that the mid-trial instruction needed to be given immediately. Dr. McDermid was the last of the plaintiff’s witnesses and the plaintiff has now closed her case. In my view, delaying the mid-trial instructions until after the next witness had taken the stand would be too late.
[38] The defendant did not argue that Dr. McDermid’s evidence should be excluded in its entirety. She is one of the plaintiff’s treating physicians and can still testify as a participant expert and give opinion in that fashion with respect to her diagnosis, prognosis and treatment recommendations made in the course of treatment.
[39] Many of the opinions that were contained in her three reports, to which she testified, in my view are still admissible under the guise of participant expert opinion evidence.
[40] I heard both counsel’s submissions with respect to a mid-trial instruction when we re-convened the day after her testimony. I advised counsel that I was simply looking for a place holder instruction, to draw to the jury’s attention that I had concerns and to some extent, what those concerns were. I would later amplify my instructions to the jury.
[41] After discussing the matter with counsel, I gave the following mid-trial instruction to the jury first thing on Thursday, April 30, 2026:
“Members of the jury, you will recall that I have qualified Dr. McDermid as an expert in clinical psychology, in the field of clinical, rehabilitation and health psychology. She has been qualified as both a participant expert witness, because she was Ms. Wallis’ treating psychologist, and as a litigation expert, permitted to give opinion evidence beyond what a participant expert might give. You will recall that as a litigation expert, Dr. McDermid signed an Acknowledgment that she had a duty to the court to give evidence that is fair, objective and non-partisan and that duty supersedes any duty to Ms. Wallis, her patient.
Over the course of Dr. McDermid’s evidence, I have determined that it is not clear what documentation she reviewed, and when she reviewed that documentation. For that reason, it is my opinion that her evidence cannot be said to be “objective” in the sense required by the Rules.
I need to review with counsel what portions of her evidence you should still be permitted to consider, given that she was one of Ms. Wallis’ treating practitioners, and what portions of her evidence you must disregard. Please do not determine how to approach her evidence until you have received further guidance from me.
When I am in position to do so, I will provide you with further instructions regarding Dr. McDermid’s evidence.”
[42] At the end of day Friday, May 1, 2026, after having heard further submissions, I gave the jury a more fulsome instruction on what parts of her evidence were still admissible, and what parts they were to disregard. I advised them that they would receive further instructions on that issue in my final charge.
[43] In this case, it is fortunate that the jury has heard opinion evidence from Dr. Iezzi, who was qualified as a litigation expert in psychology and who expressed many of the same opinions as Dr. McDermid.
Thus, while this may seem a harsh decision from the perspective of Dr. McDermid, the fundamental opinions that the plaintiff wishes to have admitted are still before the jury in this case.
Justice Spencer Nicholson
Date: May 4, 2026
CITATION: Wallis. v. Wawanesa Mutual Insurance Company, 2026 ONSC 2636
FILE NO.: CV 18-00002594-0000
DATE: 20260504
ONTARIO
SUPERIOR COURT OF JUSTICE-ONTARIO
BETWEEN:
Linda Wallis
Plaintiff
- and -
John/Jane Doe, Jack/Jill Doe and The Wawanesa Mutual Insurance Company
Defendants
MID TRIAL RULING RE EXPERT WITNESS
NICHOLSON J.
Released: May 4, 2026