Ontario Divisional Court: Permits Late Expert Reports in Malpractice Case

• The Ontario Divisional Court allowed Dr. Chung to file two expert reports in a medical malpractice case that a motion judge had previously rejected due to late service.
• The court found that while Dr. Chung's counsel made errors, penalizing the client would not serve the interests of justice, especially since the reports were filed over a year before trial.
• Key factors in the Divisional Court's decision included a prompt motion for leave, no intent to delay or gain tactical advantage, and no non-compensable prejudice to the plaintiffs.
• The ruling clarifies the court's discretion under Rule 53.08 of the Rules of Civil Procedure to accept late expert reports when it aligns with the interests of justice.
• Both parties had failed to agree on an expert report exchange schedule, as required by Rule 53.03(2.2).

The court emphasized that holding these potential mistakes against Dr. Chung would not serve the interests of justice, particularly if it hindered his ability to advance his defense.

The Ontario Divisional Court recently intervened in a medical malpractice case, `Donna Pelrine, by her Estate Trustee James Pelrine et al. v. Chung et al., 2026 ONSC 4362`, to permit the late filing of two expert reports. The appellant, Dr. Chung, had initially sought leave to deliver three expert reports — from Dr. Battel, Dr. Turcotte, and Professor Hyatt — concerning causation and damages, under Rule 53.08 of the Rules of Civil Procedure. A motion judge, in an order issued on January 30 with reasons provided on March 17, had allowed Dr. Battel's report but rejected those from Dr. Turcotte and Professor Hyatt.

Dr. Chung subsequently appealed this decision. The Divisional Court granted leave to appeal on April 22 and expedited the process, noting the impending jury trial scheduled for September. Ultimately, the court allowed Dr. Chung's appeal, granting him permission to deliver both Dr. Turcotte's and Professor Hyatt's reports. The parties mutually agreed that no costs would be awarded in the matter.

In its decision, the Divisional Court acknowledged that Dr. Chung's trial counsel had missed crucial timelines in securing the expert reports, potentially due to errors in the approach to gathering the necessary information. The court noted that counsel had provided the experts' identities and anticipated opinions prior to the pre-trial conference and had attempted to obtain the sequential information required for the reports. However, the court emphasized that holding these potential mistakes against Dr. Chung would not serve the interests of justice, particularly if it hindered his ability to advance his defense.

The court highlighted several factors supporting its decision. Dr. Chung had promptly moved for leave to file the reports, offering a consistent explanation for the delay across all three. Significantly, the reports were served more than a year before the scheduled trial date. The Divisional Court observed that the motion judge had accepted the explanation for one report but not the others, concluding that this constituted an error. Furthermore, the court found that the late service did not cause any delay to the scheduled trial, was not intended to prolong the proceedings, and did not aim to secure a tactical advantage for Dr. Chung. It also determined that the plaintiffs suffered no non-compensable prejudice and had ample time to prepare any necessary supplementary reports.

This ruling clarifies the application of Rule 53.08 of the Rules of Civil Procedure, RRO 1990, Reg 194, which governs the service of expert reports in Ontario. The Divisional Court's decision underscores the broad discretion afforded to courts in accepting late expert reports, even in instances where counsel has made errors, provided that the interests of justice are served and no non-compensable prejudice is caused to the opposing party. The court's analysis in `Pelrine v. Chung` provides valuable guidance on the factors that will be considered when evaluating motions for late service of expert evidence in Ontario, particularly in complex cases like medical malpractice proceedings.

An additional detail noted by the Divisional Court was that both sides in the `Pelrine v. Chung` case had failed to agree on a schedule for exchanging expert reports, a requirement under Rule 53.03(2.2). This highlights the importance of adhering to procedural rules regarding expert evidence, even as the court retains the discretion to remedy non-compliance when it aligns with the overarching goal of ensuring a fair hearing on the merits.

This ruling clarifies the Ontario Divisional Court's discretion under Rule 53.08 to accept late-served expert reports, even when counsel made errors, if it serves the interests of justice and causes no non-compensable prejudice. Lawyers should note the factors considered (prompt motion, lack of tactical advantage, no trial delay) when arguing for or against such motions in medical malpractice or other civil proceedings.

Source: Original reporting via Canadian Lawyer