CITATION: Donna Pelrine, by her Estate Trustee James Pelrine et al. v. Chung et al. 2026 ONSC 4362

DIVISIONAL COURT FILE NO.: DC 26-00000061-0000

DATE: 20260730

ONTARIO

SUPERIOR COURT OF JUSTICE

DIVISIONAL COURT

Firestone RSJ, Howard RSJ and McKelvey J.

BETWEEN:

DONNA PELRINE by her Estate Trustee, JAMES PELRINE, ALEXANDER PELRINE, NICOLE PELRINE, GLORIA ROBERSTON as the Litigation Administrator for the Estate of DAVID ROBERSTON, GLORIA ROBERTSON and DENISE ROBERSTON-BOOTSMA, DANA ROBERTSON, DENISE ROBERTON

Plaintiffs/Respondents

– and –

PIN CHUNG, PETER FERGUSON, JAMES TERESI, GREGORY SILVERMAN, THOMAS FORBES, MOUNT SINAI HOSPTIAL, and JANE NURSES,

Defendants/Appellants

Ronald P. Bohm

for the Plaintiffs/Respondents

J. Thomas Curry and Eli S. Lederman

for the Defendant/Appellant Dr. Pin Chung

HEARD: June 2, 2026

reasons for Decision

Firestone R.S.J.

Overview

1The Appellant Dr. Pin Chung (“Dr. Chung”) appeals from the Order of Justice Mathai (the “motion judge”) dated January 30, 2026, with reasons given March 17, 2026 (the “Motion Decision”) regarding Chung’s request for leave to file three late served reports pursuant to rule 53.08 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194 (the “Rules”).

2In this medical malpractice action, the motion judge granted Chung leave to deliver the late served standard of care report of Dr. Battel but not the late served causation report of Dr. Turcotte or the late served damages report of Professor Hyatt.

3On April 22, 2026, the Divisional Court granted leave to appeal the Motion Decision and ordered the appeal expedited given that the action is scheduled to be tried before a jury in September 2026. The appeal was heard on June 2, 2026.

4On May 25, 2026, prior to the hearing of the appeal the panel directed that counsel provide brief submissions regarding the applicability of the recent decision in 1086289 Ontario Inc. (Urban Electrical Contractors) v. Welland (City), 2026 ONCA 352 to the issues to be determined in this appeal.

5Following the hearing of the appeal the decision was reserved. By endorsement dated June 8, 2026, the panel allowed the appeal with reasons to follow. These are the reasons.

6In brief, the motion judge erred by applying the test under rule 53.08 as a strict conjunctive test and failing to properly consider the interests of justice throughout. Specifically, he failed to consider the lack of prejudice and importance of providing the trier of fact with all the necessary evidence to adjudicate the case on its merits, in determining what can constitute a reasonable explanation for the delay. In doing so, the motion judge applied rule 53.08 in a way that goes beyond its intended purpose and created a disproportionate outcome.

Standard of Review

7This is an appeal of an interlocutory order, and the appellate standard of review applies: correctness as to questions of law, and palpable and overriding error in respect to questions of fact or questions of mixed fact and law. Where there is an extricable legal principle, the standard of review is correctness. With respect to the application of the correct legal principles to the evidence, the standard is palpable and overriding error: Housen v. Nikolaisen, 2002 SCC 33, [2002] 2 S.C.R. 235, at paras. 8, 10, 19, and 27-36.

8Questions of law are questions about what the correct legal test is; questions of fact are questions about what took place between the parties; and questions of mixed fact and law are questions about whether the facts satisfy the legal tests: Canada (Director of Investigation and Research) v. Southam Inc, 1997 CanLII 385 (SCC), [1997] 1 S.C.R. 748, at para. 35.

9In the recent Divisional Court decision of Harris v. Grand River Hospital, 2026 ONSC 240, 180 O.R. (3d) 273 (Div. Ct.) [Harris], the court at para. 8 provides guidance regarding the applicable standard of review when dealing with the discretionary decision to grant leave to admit a late expert report under rule 53.08 of the Rules. The Court states:

The decision whether to grant leave to admit a late expert report is discretionary and is owed deference. A discretionary decision will be reversible where the court misdirected itself or came to a decision that is so clearly wrong that it amounts to an injustice. Reversing a lower court’s discretionary decision is also appropriate where the lower court gives no or insufficient weight to relevant considerations: Penner v. Niagara (Regional Police Services Board), 2013 SCC 19, at para. 27. However, the reviewing court is not to reweigh the relevant considerations; it may only intervene where it is satisfied that the trial judge’s exercise of discretion was unreasonable. Fresco v. Canadian Imperial Bank of Commerce, 2024 ONCA 628, at paras. 31-33.

10Here, the question is whether the motion judge misdirected himself as to the correct interpretation and application of rule 53.08. The motion judge’s exercise of discretion in applying the facts of the situation to this rule is owed considerable deference, but the interpretation of the rule itself that underpins the exercise of that discretion must be correct.

Background and Procedural History

11The underlying action arises out of the treatment and care provided to Donna Pelrine (“Ms. Pelrine”) after she developed a rare form of bone cancer in 2015. The cancer was not diagnosed until late 2015 after which time Ms. Pelrine underwent surgery at Mount Sinai Hospital. Eventually Ms. Pelrine died from complications arising from the surgery.

12The plaintiffs allege that Dr. Chung, Ms. Pelrine’s family physician, failed to inform Ms. Pelrine of the results of a CT imaging report which recommended radiographic follow-up and arrange for follow-up imaging in a timely manner. This led to a delay in diagnosis of bone cancer in the left hip. The CT imaging report was received in May 2015, and Ms. Pelrine was advised of the report in November, 2015.

13Follow-up CT imaging was conducted in December 2015, after which time Ms. Pelrine was advised she required hemipelvectomy surgery which was performed on April 18, 2016. Further surgeries were performed due to complications arising from the hemipelvectomy surgery. Ms. Pelrine died from these complications on May 2, 2016.

14The relevant chronology of events is as follows.

• April 13, 2018 - Statement of Claim issued.
• March 20, 2019 - Defendant physicians, and Hospital serve Statement of Defence and crossclaims.
• December 2-4, 2020 - Examinations for Discovery conducted.
• January 2021 - Dr. Turcotte and Professor Hyatt retained by Dr. Chung.
• February 17, 2022 - Plaintiffs serve Dr. Bond’s standard of care report regarding Dr. Chung. Counsel for defendant physicians (“Trial Counsel”) inquires whether plaintiff will be delivering reports addressing allegations against the other defendant physicians. Plaintiffs respond that they would address the issue when they received a further expert report.
• August 31, 2022 - Plaintiffs serve Dr. Clarkson’s causation expert report regarding Dr. Chung.
• December 2, 2022 - Trial Counsel again inquire whether plaintiffs will be delivering reports regarding other defendant physicians and whether action would be pursued against those defendants. No response is received.
• August 29, 2023 - Trial Counsel again inquire whether plaintiffs intend to deliver reports regarding other defendant physicians. No response is received.
• December 1, 2023 - Plaintiffs deliver Trial Record and set matter down for trial. Neither the plaintiffs nor defendants communicate for the purpose of complying with rule 53.03(2.2). This rule requires that within 60 days after the action is set down for trial, the parties shall agree to a schedule setting out dates for the service of expert reports. Rule 53.03(2.2) is not complied with.
• Early January, 2024 - Trial Counsel retains Dr. Stanton to provide expert standard of care opinion regarding Dr. Chung.
• January 8, 2024 - Plaintiffs serve Dr. Katz’s expert damages report.
• February 7, 2024 - Plaintiffs’ counsel inquire of Trial Counsel whether Dr. Chung will be delivering any expert reports and if they are interested in discussing resolution. No response is received.
• April, 2024 - Trial Counsel commences lengthy out-of-province trial which continued intermittently. Trial Counsel deposes that they were away from the office and fell behind in this case.
• June 5, 2024 - Plaintiffs’ counsel sends follow up email to Trial Counsel. Trial Counsel requests settlement brief.
• July 2, 2024 - Plaintiffs’ counsel delivers settlement brief, which only addresses negligence of Dr. Chung.
• September 4, 2024 - Trial Counsel learned that Dr. Stanton passed away in August 2024.
• September 2024 - Plaintiffs’ counsel leaves message for Trial Counsel inquiring whether defendant physicians are interested in resolving the action. No response received.
• September 24, 2024 - Plaintiffs’ counsel wrote to Trial Counsel requesting response. No response received.
• October 7, 2024 - Plaintiffs’ counsel again writes to Trial Counsel. Same day Trial Counsel emails plaintiff’s Counsel requesting telephone call.
• October 9, 2024 – During telephone call Trial Counsel advises plaintiffs’ counsel that Dr. Stanton passed away without completing the report.
• November, 2024 - Parties agree to schedule the pre-trial conference for June 19, 2025.
• February, 2025 - Trial Counsel requests a replacement standard of care report from Dr. Battel following the death of Dr. Stanton.
• May 27, 2025 - Plaintiffs deliver their pre-trial brief.
• June 12, 2025 - Defendant physicians deliver their pre-trial brief. Brief notes that expert reports are not served. In brief the experts retained were identified and a summary of their anticipated opinions was provided.
• June 19, 2025 - Pre-trial conference. Plaintiffs’ counsel advise that the action would be dismissed against all defendants except Dr. Chung. Trial Counsel requests leave to extend the deadline for serving responding reports. The pretrial judge directs that a motion be brought. Action placed on the September 2026 trial list in the Central East Region.
• June 24, 2025 - Dr. Battel’s responding standard of care report served.
• June 27, 2025 - Dr. Turcotte’s responding causation report served.
• August 19, 2025 - Professor Hyatt’s responding damages report served.
• July, 2025 - Motion for extension of time filed.
• January 8, 2026 - Motion for extension of time heard.

Amended Rule 53.08

15Rule 53.08 was amended on March 31, 2022, to read as follows:

53.08(1) If evidence is admissible only with leave of the trial judge under a provision listed in subrule (2), leave may be granted if the party responsible for the applicable failure satisfies the judge that,

(a) there is a reasonable explanation for the failure; and

(b) granting leave would not,

(i) cause prejudice to the opposing party that could not be compensated for by costs or an adjournment, or

(ii) cause undue delay in the conduct of the trial.

16Subrule 53.08(2) provides that the test in subrule (1) applies to subrule 53.03(3) regarding the timelines to serve experts reports. Rule 53.03(4)(a)-(c) provides that the time for service of expert reports under rule 53.03 may be extended or abridged: at the pre-trial conference or any conference; by the court on motion; or on the consent of the parties unless the extension would affect the scheduled trial date.

17Previously rule 53.08(1) provided that “leave shall be granted on such terms as are just and with an adjournment if necessary, unless to do so will cause prejudice to the opposite party or will cause undue delay in the conduct of the trial.”

The Motion Decision Below

18The motion judge found the test for granting leave under rule 53.08(1) is a two-part conjunctive test. At para. 48 of his reasons he states:

As it now reads, r. 53.08(1) does not involve a balancing of reasonable explanation, prejudice and undue delay. The court only engages in the balancing of relative prejudice and undue delay if the non-compliant party has established a reasonable explanation for missing the deadlines imposed by rr. 53.03(1)-(3) (see Harris v. Grand River Hospital, 2025 ONSC 282, at para. 16; Mohamud v. Juskey, 2023 ONSC 4414, at paras. 60-61).

19Under subrule 53.08(1)(a), the motion judge held that Dr. Chung, failed to establish a “reasonable explanation” for the delay in serving the causation and damages reports of Dr. Turcotte and Professor Hyatt respectively.

20The motion judge held that the two explanations given for the delay in serving the causation and damage reports, namely the unexpected death of Dr. Stanton and Trial Counsel’s inadvertent errors, were not reasonable. The inadvertences and errors in judgment were: Trial Counsel made a judgment call to wait to know if the action would proceed against all the defendant physicians before delivering the responding expert reports; Trial Counsel did not involve his colleagues to assist with the action while he was out of the province handling another trial; Trial Counsel did not raise the issue of scheduling delivery of the responding reports with plaintiff’s counsel in advance of the deadline under the Rules; and Trial Counsel did not request a later date for the pre-trial conference.

21Regarding the first explanation, the motion judge found that neither Dr. Turcotte’s (causation) nor Professor Hyatt’s (damages) reports were premised on Dr. Battel’s standard of care opinion. As a result, the late service of Dr. Battel’s report, which is partly explained by Dr. Stanton’s passing, did not have a “domino effect” on the other two reports.

22Regarding the inadvertent errors cited, the motion judge concluded that that the mistakes, whether taken individually or together, did not establish a reasonable explanation for missing the deadline. Waiting to know if the action would proceed against all defendant physicians before delivering expert responding reports was not a reasonable explanation for the delay.

23Regarding failure to engage other colleagues, there was insufficient evidence to explain why co-counsel on the file could not assist when Trial Counsel was out of the province. Both counsel of record have a responsibility to ensure the deadlines are met. In any event the characterization of this as an error in judgment is an attempt to transform an explanation that would normally be described as “inattentiveness” into “inadvertence” which is more readily found to be a “reasonable explanation.”

24Finally, the motion judge found that agreeing to a June 2025 pre-trial is not a reasonable explanation for missing the service deadline. Dr. Chung should have known in July 2024 that the plaintiff’s claim was limited to his alleged negligence. This was nearly 4 months before the pre-trial conference.

25Based on the determination that there was not a reasonable explanation for the delay, the motion judge dismissed the motion for the requested extension of time for the late served causation and damage reports.

26For completeness, the motion judge went on to consider the second stage of the test under subrule 53.08(1)(b), namely prejudice to the opposing party that could not be compensated for by costs or an adjournment, or undue delay in the conduct of the trial. The motion judge concluded at para. 107 of his reasons, that “had I found that a reasonable explanation was provided with respect to Dr. Turcotte’s and Dr. Hyatt’s reports, I would have found that the interests of justice favour the admission of the reports.”

27At paragraphs 108-109 the motion judge concludes:

I recognize that my ruling appears harsh. The last of the defendant’s reports were served just over a year before the trial is scheduled to commence. Even if all three reports were admitted, there is little risk that the trial would be adjourned. In the circumstances, one could reasonably ask why the defendant is being denied an extension to serve his causation and damages reports?

The answer to this question can be found in the text of r. 53.08. Both the plain text of the rule and the weight of the authority from the court confirms that the test is conjunctive. If the test required a balancing of a reasonable explanation, prejudice and undue delay, then my ruling would have been different.

Positions of the Parties

Appellant’s Position

28Mr. Curry, who was not involved in this action until the underlying motion submits on behalf of Dr. Chung, that the motion judge erred by failing to rely on the Divisional Court decision in Harris, which rejected the strict conjunctive test adopted by the motion judge in favour of a balanced approach to the interpretation and application of rule 53.08.

29They highlight that in Harris, this court overturned the proposition relied on by the motion judge that a court hearing a motion under rule 53.08 should not engage in a balancing of reasonable explanation, prejudice and undue delay, but rather, should apply a strict conjunctive test. Harris confirmed that courts must take a balanced approach that treats the interests of justice as paramount.

30The appellant also submits that the motion judge imposed an overly strict interpretation of what constitutes a reasonable explanation and misapprehended the factual and legal relationship between the expert reports on the standard of care, causation, and damages.

31Counsel’s mistake or error in judgment should be considered from the perspective of the party who will suffer the consequences. In the circumstances of this case, where there is no prejudice to the opposing party or undue delay, and significant prejudice to the defendant Dr. Chung, an explanation on the very low end of what is reasonable may and should be accepted. Dr. Chung’s ability to defend on the merits against the allegations of professional negligence should not be irrevocably placed in jeopardy because his counsel made a mistake.

32Further, the explanation for the delay was the same for all three reports and the reports must build sequentially upon one another. Trial Counsel indicated that it was solely his inadvertence and error in judgment that led to him not delivering the expert reports in accordance with the rules. Trial Counsel concluded he should wait to know if the case would proceed against all defendant Physicians before delivering expert reports. His belief was that the content of the reports would be different if the allegations were made against all the defendants. Accordingly, the motion judge’s finding that there was a reasonable explanation for delay in the service of the standard of care report must necessarily extend to the responding reports on causation and damages.

33Trial Counsel was not seeking a tactical advantage or to delay the proceeding. Further, following the Pre-Trial Conference he acted swiftly to engage the assistance of senior counsel, finalize the responding reports from the experts already retained, and proceed with the motion for leave.

34The motion judge failed to consider the overall interests of justice. The motion judge’s approach was unduly harsh and led to a situation where Dr. Chung is seriously prejudiced. Such prejudice does not advance the goals of rules 1.04, 2.03, or 53.08. Had the motion judge considered the interests of justice in advancing the fundamental goal of resolving disputes on their merits as an essential part of the test for leave under rule 53.08, leave would have been granted.

35It is submitted that the decision in Urban Electrical Contractors supports the position of the appellant. The Court of Appeal rejected the unduly harsh formulaic test set out in Handley Estate v. DTE Industries Limited, 2018 ONCA 324, 421 D.L.R. (4th) 636, and restored the applicable governing law to a principled and flexible footing that was to be applied in a manor that is attentive to context, guided by proportionality, and directed toward the fair administration of justice. This approach is consistent with the dominant trend in the case law, including the recent decision in Harris. Consistent with Harris, many of the reported decisions on rule 53.08 since the 2022 amendment apply broader discretion when considering the inadvertence of counsel and adopt a balancing approach that takes into account the interests of justice.

Respondents’ Position

36The respondents submit that the motion judge correctly applied rule 53.08 given it is well established that the test under rule 53.08 is conjunctive. The rule does not require a balancing of reasonable explanation, prejudice and undue delay. Rather, a reasonable explanation must be provided. The Divisional Court’s decision in Harris does not support the application of a balancing approach, as asserted by the appellant.

37As stated in Agha v. Monroe, 2022 ONSC 2508, 23 C.C.L.I. (6th) 118, the purpose of the amendment to rule 53.08 is to send a very loud and clear message to all sides of the Bar, that expert reports are to be served in a timely manner and in accordance with the provisions of rule 53.03(1) and (2).

38It is further argued that despite not citing the Divisional Court decision in Harris, the motion judge conducted a thorough analysis that follows the principles in Harris. Harris affirms that the change to rule 53.08 was meant to prevent inattentiveness, delay, unproductive pre-trials and trial adjournments. The new rule permits a judge to refuse leave even if there is no prejudice and that prejudice is still a relevant consideration, and a court must always consider the overall interests of justice.

39The respondents submit that the motion judge’s determination of what constitutes a reasonable explanation is a finding of fact and is owed deference absent palpable and overriding error. The motion judge found that the appellant intentionally chose to disregard deadlines imposed by the rules and serve their reports after the pre-trial conference. The motion judge was critical of the conduct and behaviour of Trial Counsel and made findings which are entitled to deference.

40The respondents submit that the defendant’s attempts to self-describe or label their decision as inadvertence, as opposed to inattentiveness was rejected by the motion judge who found such claims to be false and an example of how labels can potentially obscure the real issue of whether the explanation is reasonable or not. Describing deliberate choices as inadvertent mistakes or errors in judgment is unreasonable and negate the salutary effects of rule 53.08(1).

41Denying leave to file the causation and damage reports in this medical malpractice action is in the interests of justice. The motion judge weighed his decision against the interests of justice and concluded that while some mistakes or errors in judgment may be elevated to the level of reasonable explanation, not all of them will. To engage the balancing approach asserted by the appellant would revert rule 53.08 back to an escape clause and perpetuate the crisis faced by our civil justice system. An intentional feature of rule 53.08 is that there will be situations where a client is burdened with the sins of counsel.

42The respondents argue that the Court of Appeal in Urban Electrical Contractors overturned the Handley Estate rule because it was unduly rigid which was lacking in judicial discretion, mandating results irrespective of its implications and the parties’ conduct. The reasons for the amendments to rule 53.08 are similar to the reasons why rule 49.14 was amended. As with Handley Estate, rule 53.08 was too rigid and exceptionless and mandated, irrespective of conduct, leave for the late filing of expert reports. This was viewed as an escape clause and resulted in unproductive pretrials, trial adjournments, backlogs and the wasting of valuable resources. This created a crisis in the justice system. The rule change affords a judge discretion to evaluate the conduct in issue. The motion judge did follow the accepted principles in Urban Electrical Contractors. He liberally construed the rule and denied leave because the defendant did not offer any reasonable explanation for deliberately disregarding the time requirements.

43The trier of fact will not be deprived of any expert causation or damage opinions or evidence. While the defendant may prefer to call their own experts, there is no property in a witness and multiple experts on a subject area are neither necessary nor required. They will be able to cross-examine the causation and damages experts called by the plaintiffs. Expert witnesses are required to be impartial. The rules were not made to be ignored and there should be consequences. Here there was an intentional decision to serve reports late without good reason. To admit the reports will serve to undermine the integrity of the administration of justice in even if no demonstrable prejudice or undue delay and ignore the legislative intent behind the rule change.

Analysis

Guiding Principles to the Interpretation and Application of Rule 53.08

44While the amended version of rule 53.08 is intended to limit the situations in which late filed expert reports will be permitted, the test must be applied with an emphasis on the interests of justice throughout. The strict conjunctive test applied by the motion judge failed to properly balance the relevant considerations as required by this court in Harris.

45The change in wording from the mandatory language of “shall be granted” to the permissive language of “may be granted” as well as the additional requirement that the delay be reasonable was clearly intended to create a stricter framework for the late admission of expert reports. This was necessary to address a culture of delay and the chronic problem of counsel submitting late served expert reports as a matter of course, in many cases for strategic reasons. The shift from the mandatory language (shall) to permissive language (may) demonstrates that the application of the rule is a discretionary exercise with the intended purpose of reducing wasted and unproductive pretrial conferences and avoiding unnecessary and last-minute trial adjournments.

46Rule 53.08 is to be interpreted and applied in a manor consistent with the overall objective the rule change was meant to achieve. In applying the rule care must be taken to avoid disproportionate outcomes. A formalistic approach to the interpretation and application of the rule devoid of or lacking in interest of justice considerations in accordance with rule 1.04 is to be avoided. A contextual and balanced approach is to be taken in the exercise of discretion when making the determination under the rule.

47While the plain reading of the new test under rule 53.08 is conjunctive and requires both a reasonable explanation and lack of prejudice, the rule as a whole is to be read and applied with regard to the interests of justice. Notwithstanding that the question of whether prejudice would result from late service of the expert reports is a separate factor under rule 53.08(1)(b), the question of prejudice is inherent to the impact of the decision on the interests of justice. Rule 1.04 is to be applied throughout the entire application of the rule, and not just to subrule 53.08(1)(b).

48Implicit in the interest of justice framework is the principle that proceedings be fairly heard and decided on the merits by ensuring, where possible and appropriate in the circumstances, that the trier of fact have the necessary evidence before them. The rule change was not intended to impede the fair and just determination of the issues on their merits.

49It is for this reason that in determining whether the explanation for the delay is a reasonable one, the explanation should not be considered in a vacuum. The explanation must be considered in light of all the surrounding circumstances and a determination made regarding whether the explanation is reasonable in the context of those circumstances and interest of justice considerations. The rule requires a reasonable explanation, not a perfect explanation and is to be determined within the context of the overall purpose of the new rule and the concerns it was meant to address.

50In Harris the Divisional Court states at para. 29 as follows:

While the new rule permits a judge to refuse leave even if there is no prejudice to the opposing party, this does not mean the absence of prejudice is irrelevant. In deciding whether to grant leave for an abridgement of time, it is always important to consider the overall interest of justice. Pursuant to r. 1.04, the rules are to be liberally construed “to secure the just, most expeditious and least expensive determination of every civil proceeding on its merits.” As Sharpe J.A. reminds us in 1196158 Ontario Inc. v. 6274013 Canada Ltd; 2012 ONCA 544, at para. 19, “procedural rules are the servants of justice not its master.” He goes on to say:

We should strive to avoid a purely formalistic and mechanical application of timelines that would penalize parties for technical non-compliance and frustrate the fundamental goal of resolving disputes on their merits. As Laskin J.A. stated in Finlay v. Van Paassen (2010), 101 O.R. (3d) 390, [2010] O.J. No. 1097, 2010 ONCA 204, at para. 14, “the Rules and procedural orders are construed in a way that advances the interests of justice and ordinarily permits the parties to get to the real merits of their dispute”.

51It is important to note that the motion judge did not have the benefit and guidance of the Divisional Court’s decision in Harris, which overturned the lower court’s decision, a decision upon which the motion judge relied when deciding the motion before him.

52This approach to the interpretation of rule 53.08 is reinforced by the reasoning in the recent Court of Appeal decisions in Urban Electrical Contractors. In these appeals the court reconsidered the framework governing the disclosure of partial settlement agreements in multi-party civil litigation and the continued validity of the rule articulated in Handley Estate.

53While Urban Electrical Contractors deals with a different issue under a different rule focussing on the doctrine of abuse of process, it provides helpful guidance and is instructive to the issues to be determined in this appeal. In Urban Electrical Contractors the court overturned a previous decision to allow for a more contextual and discretionary approach to determining whether an abuse of process has occurred and if so what remedy to apply: Urban Electrical Contractors, at paras. 164-166.

54In Urban Electrical Contractors, in order to prevent unjust outcomes, the court moved away from a strict, rigid framework in which cases were not being adjudicated on their merits because of a technical breach: paras. 66-70. In their reasoning the court specifically rejects categorical considerations and obligatory remedies in favor of a discretionary, less formulaic fact-based analysis that focuses on the resulting prejudice and impact on the justice system: Urban Electrical Contractors, at paras. 15-17. As the court states at para. 17: “A doctrine designed to serve the ends of justice, applied mechanically, acts contrary to its own animating objective.”

55The reasoning in Urban Electrical Contractors underpins the approach to the interpretation of the Rules of Civil Procedure generally. These principles are further demonstrated by rules 1.04 and 2.03, and rule 53.08 is to be interpreted based on the same framework. Applying that reasoning , rule 53.08 is to be applied “in a manner that is attentive to context, guided by proportionality, and directed toward the fair and orderly administration of justice”: Urban Electrical Contractors, at para. 170.

56This approach to the interpretation and application of rule 53.08 is consistent with the modern approach to statutory interpretation as set forth in Trebell v. Canadian Life Assurance Company 2026 ONCA 481, at para. 31, where the court states “[t]he modern approach to statutory interpretation requires the meaning of a statutory provision to be determined by reference to its text, context and purpose: Telus Communications Inc. v. Federation of Canadian Municipalities, 2025 SCC 15, 502 D.L.R. (4th) 59, at para. 30.” Here, the context and purpose of the rule inform the interpretation of the test and demonstrate the necessity of considering the interests of justice throughout.

57The motion judge at para. 48 of his decision relied on the underlying decision in Harris in holding that:

[Rule] 53.08, does not involve a balancing of reasonable explanation, prejudice and undue delay. The court only engages in the balancing of relative prejudice and undue delay if the non-compliant party has established a reasonable explanation for missing the deadlines imposed by rr.53.03(1)-(3) (see Harris v. Grand River Hospital, 2025 ONSC 282 at para. 16; Mohamud v. Juskey, 2023 ONSC 4414, at paras. 60-61.

This is precisely the reasoning that was overturned by the Divisional Court in Harris.

58The motion judge at para. 94 of his decision expresses the concern that if he was to accept [that inattentiveness to a file, can constitute a reasonable explanation for delay because of counsel’s practice demands], then r. 53.08(1) would effectively revert back to being an “escape clause”. This echoes the concerns of the motion judge in Harris, at para. 17 where she states in part “[t]o grant the order abridging the time for service of the expert report in all these circumstances would render the relevant Rule entirely toothless.”

59This concern was also rejected by the Divisional Court in Harris, at paras. 26-28 where they conclude that the motion judge in that case erred by not considering the overall interests of justice when applying rule 53.08. All the surrounding circumstances, which include the relevant timeline of events, along with the broader interest of justice considerations are to be considered with respect to the application of the entire rule.

60Such an approach does not remove or soften the intended purpose of the rule change or remove the requirement that there be a reasonable explanation. Rather it ensures that the court undertakes a more thorough analysis that fully accounts for the interests of justice in making the final determination.

61Rule 53.08 was amended to create a stricter framework for the extension of time to deliver expert reports. The old version of the rule was too permissive and led to the automatic admission of expert reports regardless of the reason why they were late. This created a culture where the timelines prescribed under rule 53 to serve these reports were treated as no more than suggestions that could be ignored for any reason.

62Reports that are delivered late for nefarious or tactical reasons were certainly intended to be captured by the new rule, as were situations where there has been a deliberate disregard for the rule with out any reasonable explanation or justification at all. In such circumstances the denial for leave is appropriate. However, the explanation for the delay in and of itself should not overwhelm the other elements of the analysis or overtake the court’s primary function of adjudicating cases on the merits. It is within this framework that rule 53.08 is to be interpreted and applied. In this analysis, mistakes, errors in judgement, and even a deliberate decision to deliver an expert report late that is grounded in a reasonable belief it is necessary in the circumstances, may amount to a reasonable explanation depending on the extent of the resulting prejudice or delay, and any other surrounding circumstances which include the timeline of events and interest of justice considerations.

Application to the Facts of the Case

63In deciding whether the explanation for the delay is reasonable, the characterization of indiscretions by a lawyer as either inattentive or inadvertent as a determining factor is too strict, rigid, and arbitrary. The motion judge’s analysis put significant emphasis on this distinction. The determination of reasonableness must be balanced and based on all the relevant surrounding circumstances. This is especially so in medical malpractice cases where the plaintiff’s or defendants’ case may turn on whether the expert evidence is admitted, given its direct effect on their ability to advance or defend the case.

64As the Court of Appeal states in Liu v. Wong, 2016 ONCA 366, at para. 14:

Medical malpractice cases are complex – even where they may appear simple to the eye of a layperson – and judges and juries lack the expertise necessary to assess difficult questions such as causation, standard of care, and breach of the standard of care, without the assistance of expert reports. For that reason, this court and others have stated that aside from the “clearest of cases” the absence of [] expert evidence in support of the plaintiff’s medical malpractice claim is fatal: see Larman v. Mount Sinai Hospital, 2014 ONCA 923.

65In this case the standard of care report of Dr. Battel was served five days after the pretrial conference on June 24, 2025 and leave was granted. The causation report of Dr. Turcotte and damages report of Professor Hyatt were served on June 27, 2025 and August 19, 2025 respectively and leave was not granted. The record confirms that the death of Dr. Stanton did not contribute to the delay and that while the same explanation for the delay was given for all three reports it was accepted for one but not the others.

66All three reports were delivered more than a year before the scheduled trial date allowing sufficient time for the Plaintiffs to obtain any necessary supplementary reports. The late service did not delay the scheduled trial date and there is no non-compensable prejudice. Late service was not done to gain a tactical advantage or to delay the proceeding, but rather for what Trial Counsel believed to be a legitimate reason, namely, to obtain the information he believed necessary for the experts to finalize their reports given they build sequentially upon one another. Additionally, neither party complied with the requirement of agreeing to a schedule for the exchange of expert reports in rule 53.03(2.2). This was a relevant factor that needed to be considered: Harris at para. 21.

67Prior to the Pre-Trial Conference, Trial Counsel did provide both the identity of their experts as well as a summary of their anticipated opinions. The plaintiff’s decision to let the other physicians out of the action was not formally confirmed until the Pre-Trial Conference. The reports were subsequently served in June and August 2025. The motion for leave was brought promptly. While Trial Counsel may have made mistakes in his approach to obtaining the expert reports, and this caused him to miss the prescribed timelines, in this case it is not in the interests of justice to hold these mistakes against Dr. Chung, especially where the result is likely to be fatal to his ability to advance his case.

68Respectfully, I find that the learned motion judge misdirected himself by failing to correctly apply and give sufficient weight to the applicable principles in determining whether leave should be granted pursuant to rule 53.08. The motion judge himself found that had he had the discretion to take a more holistic approach, balancing prejudice to both parties with the question of reasonable explanation, his decision would have been different. The Divisional Court’s decision in Harris makes it clear that he did have that discretion. While he did not have the benefit of the Divisional Court’s reasoning at the time, the motion judge fell into error by failing to apply the applicable interest of justice considerations and balancing approach to the entirety of the rule 53.08 analysis.

Disposition

69As confirmed in the courts endorsement dated June 8, 2026, the appeal is allowed and Dr. Pin Chung is granted leave to deliver the reports of Dr. Turcotte (causation) and Professor Hyatt(damages). As agreed between the parties, there is no order as to costs.

Firestone RSJ.

I agree _______________________________

Howard RSJ.

I agree _______________________________

McKelvey J.

Released: July 30, 2026

CITATION: Donna Pelrine, by her Estate Trustee James Pelrine et al. v. Chung et al. 2026 ONSC 4362

DIVISIONAL COURT FILE NO.: DC-26-00000061-0000

DATE: 20260730

ONTARIO

SUPERIOR COURT OF JUSTICE

DIVISIONAL COURT

Firestone RSJ, Howard RSJ and McKelvey J.

BETWEEN:

DONNA PELRINE by her Estate Trustee, JAMES PELRINE, ALEXANDER PELRINE, NICOLE PELRINE, GLORIA ROBERSTON as the Litigation Administrator for the Estate of DAVID ROBERSTON, GLORIA ROBERTSON and DENISE ROBERSTON-BOOTSMA, DANA ROBERTSON, DENISE ROBERTON

Plaintiffs/Respondents

– and –

PIN CHUNG, PETER FERGUSON, JAMES TERESI, GREGORY SILVERMAN, THOMAS FORBES, MOUNT SINAI HOSPTIAL, and JANE NURSES,

Defendant/Appellant Dr. Pin Chung