The Alberta Court of Appeal's decision in Terrigno v Weal, 2026 ABCA 300, is a reminder that choosing litigation counsel involves more than finding the right advocate. It also requires considering whether that lawyer could become part of the evidence.

The case arose from defamation actions involving allegedly defamatory online statements and two disputed videos. The plaintiff's lawyer appeared in the videos. The defendants indicated that they intended to call the lawyer as a witness regarding matters within his personal knowledge, including the authenticity of the videos.

A chambers judge ordered that the lawyer and his firm be removed from the record. The Alberta Court of Appeal upheld that decision.

The Court recognized the importance of a party's right to choose its own counsel. However, that right is not absolute. Courts must also protect the fairness of the trial process.

The key question was not whether the lawyer could possibly be called as a witness. The question was whether he was likely to be a witness on issues that were material to the dispute. The Court concluded that he had first-hand knowledge relating to evidence that was central to the litigation. The fact that other witnesses might also be available did not prevent the defendants from seeking that evidence from him.

Practical Takeaways for Businesses and Executives

1. Assess witness risk before retaining counsel

When litigation is anticipated, consider whether proposed counsel has any direct involvement in the events, communications, transactions or documents that may become evidence. A lawyer who becomes a potential witness may not be able to continue acting as advocate.

2. Identify issues early

A late-stage change in counsel can be costly and disruptive. New lawyers must become familiar with the facts, the history of the dispute and the litigation strategy. Early assessment can help avoid that risk.

3. Other witnesses may not solve the problem

The existence of alternative witnesses does not necessarily eliminate an advocate-witness concern. If a lawyer has relevant first-hand knowledge, another party may still have a legitimate basis to call that lawyer as a witness.

4. Consider the impact on the entire firm

Depending on the circumstances, the consequences may extend beyond the individual lawyer. Organizations should consider whether an advocate-witness issue could affect the firm's ability to continue acting.

5. Address concerns at first instance

Decisions relating to counsel disqualification are highly discretionary. As a result, appellate courts are often reluctant to interfere unless an error in principle has been shown. Issues identified and addressed early are generally easier to manage.

The application of these principles will depend on the particular facts of each case and should be considered with legal advisers at an early stage. Please consult with any member of our team on this or other commercial litigation issues.