The Interests of Justice Prevail: Rule 53.08 and Admitting Evidence with Leave
In a medical malpractice action, Donna Pelrine, by her Estate Trustee James Pelrine et al. v. Chung et al., 2026 ONSC 4362 (CanLII), Dr. Pin Chung requested leave under Rule 53.08 of the Rules of Civil Procedure, to admit into evidence three late served expert reports, which included a standard of care report, a causation report and a damages report. The motion judge only granted leave to admit the standard of care report.
This past June, the Divisional Court reviewed the motion judge’s decision and ruled that the motion judge erred by viewing the test as a strict conjunctive test instead of using a balancing approach and considering the interests of justice. By primarily focusing on the reason for the technical breach, denying leave would have prevented the trial judge from adjudicating the medical malpractice case on its merits.
Amendments to Rule 53.08
In March 2022, Rule 53.08 was amended 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 the 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.
Subrule 53.08(2) states that the test in subrule (1) applies to subrule 53.03(3), which governs the deadline of when expert reports must be served.
Prior to the amendment, rule 53.08(1) stated 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 mandatory language of “shall be granted” in the prior wording of the rule resulted in a culture where expert reports were routinely served late. By requiring that the delay be reasonable and changing the wording to the more permissive language of “may be granted,” the amendment created a stricter framework to reduce needless delays and ensure judges are using their discretion to provide leave only when necessary.
Granting Leave Does Not Remove or Soften the Intended Purpose of the Rule Change
The motion judge explained in his decision that he was not to engage in a “balancing of reasonable explanation, prejudice and undue delay,” as this assessment was only to occur after the non-compliant party established that there was a reasonable explanation for failing to adhere to the expert report deadlines. As the motion judge did not find that the reason for delay was reasonable, he did not proceed to other steps of the test and denied leave.
The Court referenced the recent Divisional Court decision of Harris v. Grand River Hospital, 2026 ONSC 240 [Harris], to emphasize that the interests of justice and all the surrounding circumstances including the relevant timeline of events, are to be considered throughout the test for rule 53.08.
While the motion judge in this matter did not have the Divisional Court’s reasoning in Harris, the motion judge did state in his reasons that if the non-compliant party provided a reasonable explanation for the delay, he would have found that the interests of justice favoured the admission of all of the reports.
As a result, the Divisional Court allowed the appeal and granted leave since the test for rule 53.08 grants judges the discretion to take a holistic approach when assessing whether to admit evidence, such as expert reports.
The Court highlighted that the reasoning for this approach is reinforced by the recent Court of Appeal decision, 1086289 Ontario Inc. (Urban Electrical Contractors) v. Welland (City), 2026 ONCA 352 [Urban Electrical Contractors]. While Urban Electrical Contractors focused on rule 49.14 of the Rules of Civil Procedure, the Court of Appeal similarly rejected the use of a strict, rigid framework for a more discretionary and contextual approach that examines both the resulting prejudice and the broader implications for the administration of justice. Notably, the Court of Appeal emphasized in paragraph 17, “A doctrine designed to serve the ends of justice, applied mechanically, acts contrary to its own animating objective.”
(Please see our blog discussing the overturning of the Handley Estate Rule in Urban Electrical Contractors for more information, From Axe to Scalpel: Ontario Court of Appeal Overrules the Handley Estate Rule – Rogers Partners LLP).
As for Dr. Chung’s case, the nature of medical malpractice cases and the benefit of expert reports when explaining technical medical information to the court and jury favoured admitting the late served expert reports. Additionally, the three reports were served a year in advance of the scheduled trial allowing the Plaintiffs time to serve any supplementary reports they deemed necessary.
Dr. Chung’s experts were also identified prior to the Pre-Trial Conference, and a summary of their anticipated opinions were provided. The Court also highlighted that neither party agreed to a schedule for exchanging their expert reports, as required by rule 53.03(2.2).
As a result, the Court overturned the motion judge’s decision and granted leave to admit all three expert reports.
This decision emphasizes that the changes made to rule 53.08 has created a stricter test to deter unnecessary delays but that the interests of justice must remain at the forefront of this determination to ensure a fair and orderly administration of justice.