Executive Summary: Key Legal and Evidentiary Issues

• The applicants sought leave to appeal an interlocutory judgment allowing the respondent to amend its originating application.

• They argued the amendments infringed accountant-client privilege and statutory confidentiality obligations.

• The appellate court rejected the new legal argument regarding professional secrecy as it had not been raised at trial.

• Alleged prejudice from the amended pleading did not meet the standard of irreparable harm under article 31 C.p.c.

• The request to appeal the denial of a motion to dismiss for abuse was also found non-appealable at this stage.

• The court found no exceptional circumstances justifying intervention and denied leave to appeal with costs.

Facts and procedural background

In St-Jean v. DCA, Chartered Professional Accountant Inc., 2025 QCCA 593, Luc and Benoit St-Jean sought leave to appeal a procedural decision issued by the Superior Court during ongoing civil proceedings initiated by DCA, Chartered Professional Accountant Inc. The judgment being contested had granted DCA permission to substantially amend its originating application and had simultaneously denied the St-Jeans’ motion to dismiss the action as abusive under article 51 of the Code of Civil Procedure (C.p.c.).

The applicants argued that the added allegations—amounting to 387 new paragraphs—caused irreparable harm by violating professional secrecy and confidentiality provisions in Quebec's Tax Administration Act and the federal Income Tax Act. They claimed the modifications transformed the nature of the dispute and overwhelmed the litigation with disproportionate detail and allegations.

Legal analysis and findings

The Court of Appeal, per Justice Frédéric Bachand, first reiterated that decisions permitting amendments to pleadings are generally not appealable unless they cause irreparable harm. The applicants’ argument regarding the violation of professional secrecy was rejected because it had not been raised in first instance, thereby denying the respondent an opportunity to respond or introduce contrary evidence.

The court emphasized the long-standing rule that new legal issues should not be raised for the first time on appeal unless no prejudice would result. In this case, the alleged breach of confidentiality impacted third parties and was not clearly substantiated. The claim of harm was speculative and lacked evidentiary support.

As for the proportionality argument regarding the scale of the amendment, the trial judge had explicitly acknowledged the potential imbalance and still concluded that the modifications were justified in the interest of justice. The appellate judge found no unreasonable exercise of discretion in that assessment.

Finally, on the denial of the abuse of procedure claim, the Court reaffirmed that interlocutory decisions rejecting motions under articles 51 and 168(2) C.p.c. are not appealable unless they raise new and important questions of law. In this case, the applicants failed to demonstrate any such issue, merely asserting that the judge had erred in refusing to strike out the claim.

Conclusion and outcome

Justice Bachand dismissed the motion for leave to appeal, finding no exceptional circumstances or irreparable harm justifying early appellate intervention. He held that the issues raised were either procedurally barred or lacked sufficient gravity. Each party was ordered to bear its own costs. The case underscores the narrow path for appealing procedural rulings and reinforces that unsubstantiated claims of professional secrecy infringement will not suffice without a proper factual and legal foundation.