Executive Summary: Key Legal and Evidentiary Issues

• Admissibility of expert reports at a preliminary stage under article 241 of the Code of Civil Procedure, applying the four R. v. Mohan criteria (relevance, necessity, absence of an exclusionary rule, and sufficient qualification of the expert).
• Foreclosure of a party from producing expert evidence, assessed under the discretionary criteria set out in Modes Striva Inc. c. Banque Nationale du Canada.
• Whether a redacted damages report (the Accuracy Report) compromised the defendants' right to a full and complete defence and to procedural fairness.
• Allegations of dilatory conduct and lack of diligence by the plaintiffs in disclosing their expert evidence and in resolving confidentiality measures.
• Usefulness of a purely theoretical expert report (the Brunet Report) on the psychological effects of employee turnover, absent any application of its principles to the specific facts of the case.
• Distinction between the preliminary admissibility of an expert report and its probative value, the latter being reserved for the trial judge.

Facts of the case

Marsh Canada ltée and Marsh & McLennan Companies, Inc. are suing BFL Canada Services de risques et assurances inc., its regional vice-president for Eastern Canada, and nine former employees who joined BFL. The plaintiffs allege unfair competition, illegal appropriation of confidential data and personal information, and prohibited solicitation of employees and clients. In addition to injunctive orders, they claim damages of $10,413,000. The events at the heart of the dispute occurred in the spring of 2024, and the plaintiffs first instituted proceedings for an interlocutory injunction, a permanent injunction and damages in June 2024, later converting the action into one for a permanent injunction and damages in early December 2025. In the present application, heard on May 27, 2026, the defendants asked the Superior Court of Québec (Justice Gabrielle Brochu) to dismiss two expert reports disclosed by the plaintiffs: the report of Professor Luc Brunet dated December 3, 2025, on the organizational and personal effects of staff loss (the Brunet Report), and the Accuracy report dated December 5, 2025, quantifying damages (the Accuracy Report). The defendants also sought an order foreclosing the plaintiffs from producing any further expert report, arguing that the plaintiffs had not respected their procedural undertakings or the Court's orders.

Contractual clauses and procedural rules at issue

Two sets of provisions were central. First, the Accuracy Report quantifies part of the claimed damages using the formula found in the penal clauses contained in the contracts of two of the defendants; its author, David Pelletier, also applies a second method he calls the "But For Approach," comparing pre-tax cash flows under a foreseeable scenario with those flowing from the actual situation. Second, the application turned on article 241 of the Code of Civil Procedure, which permits the dismissal of an expert report at a preliminary stage for "irregularity, serious error or bias," the term "irregularity" referring to the four admissibility criteria from R. v. Mohan: relevance, necessity to assist the trier of fact, absence of any exclusionary rule, and sufficient qualification of the expert. The foreclosure question was governed by the criteria in Modes Striva, which direct the judge to weigh the reasons for the late disclosure, the prejudice to each party, the responsibility of counsel and client for the delay, the conduct of the file, and the sound administration of justice.

The court's reasoning and analysis

Regarding the Accuracy Report, the Court found it manifestly relevant, necessary to the trial judge, not excluded by any rule, and prepared by an apparently sufficiently qualified firm. The Court rejected the argument that the defendants' rights to a full defence and procedural fairness were compromised: although the defendants did not personally hold every detail of the calculations, they had a clear breakdown of the claim — contractual penalties, lost profits (lost clients and revenue from new clients not obtained), salary increases, social benefits and retention bonuses — together with the detailed originating application of 73 pages and 466 paragraphs. Their lawyers and experts, moreover, had access to an unredacted copy of the report since February 16, 2026, and the defendants themselves received a redacted version on March 3, 2026. The prejudice the defendants suffered from the redactions was manifestly less than what the plaintiffs would suffer if deprived of their damages expertise. The Court also found no dilatory manoeuvres or lack of diligence: the delays were not unreasonable, and the confidentiality issue was progressing, with a joint table on the redacted information nearly completed following the Court's April 16 order. As for the Brunet Report, the Court held that its theoretical exposition of the psychological consequences of staff turnover would usefully assist the trial judge in assessing the plausibility of the damages claimed and the causal link between the alleged solicitation of employees and its harmful effects on the workplace. The absence of application of those principles to the specific facts was not a bar to admissibility, since the trial judge could perform that exercise, and nothing prevented the defendants from testing the report's principles through a counter-expertise. The Court noted, without deciding the point, that the report as drafted stands in lieu of testimony and does not contemplate the expert applying his principles to particular facts at trial; its probative value will fall to the trial judge.

Ruling and overall outcome

For these reasons, the Tribunal dismissed the defendants' application to reject the expert reports and for foreclosure, "the whole with costs." The plaintiffs, Marsh Canada ltée and Marsh & McLennan Companies, Inc., were therefore the successful parties on this application, retaining the right to rely on both the Accuracy Report and the Brunet Report in support of their $10,413,000 damages claim, which remains to be adjudicated on the merits. While costs were awarded in the plaintiffs' favour, no exact monetary amount was specified in the judgment.