Fraser MacLean, a high net worth Vancouver lawyer of MacLean Family Law is once again at the centre of one of Canada’s most watched debates on artificial intelligence and legal ethics. As a recent recipient of ‘Canadian Lawyer’s 2025 Top 25 Most Influential Lawyers‘, Fraser’s sought after opinion was underscored by his role in discovering opposing counsel had cited hallucinated case law.
Lawyer who banned firm from using AI tools responsible for contractor’s AI hallucinations
The appellate court ruled that lawyers bear ultimate responsibility for court filings containing “hallucinated” AI case law, even though the factum had been prepared by a third-party contractor who may have lied to the lawyer about not using a large language model tool.
The case follows the landmark Zhang v. Chen decision in British Columbia, in which MacLean and the team at MacLean Law exposed fabricated case citations by opposing counsel, making Canadian legal history as the first known court ruling in the country to address AI-generated errors.
The lawyer “bears ultimate responsibility” for submitting hallucinated AI case law
“No matter how good someone else may be who is preparing work on your behalf… it is the lawyer’s duty to make sure that you put good work forward and have checked that work to ensure it is accurate,” said MacLean. This is the case “whether that work is prepared by a contractor, a paralegal, or another lawyer at your office.”
The Alberta Court of Appeal clarified that practice management obligations now require lawyers to include the time required to cross-verify any case authorities generated with the assistance of large language models. Failure to do this can result in submissions being struck, cost sanctions, or even referrals to law societies.
The Stakes are Higher with Generative AI
As firms of all sizes navigate the risks and efficiencies of generative AI, the stakes are massive. For MacLean, whose client base often involves complex property division, business assets, and international holdings, the issue highlights the need for diligence, precision, and integrity.
MacLean Law Named Best Canadian Family Law Firm By Canadian Lawyer Magazine
With his combination of courtroom victories, industry recognition, and focus on the evolving challenges of technology in law, Fraser continues to distinguish himself as one of Canada’s leading voices at the intersection of legal innovation and high net worth family litigation. As lead counsel in an ultra-high net worth case Zhang v. Chen, 2023 BCSC 2206 involving up to $70-90 million in assets, Fraser successfully obtained one of the highest interim support awards in BC history for his client.
About high net worth divorce and international family lawyer Fraser MacLean:
Fraser’s AI advocacy garners headlines, and his day-to-day work in family law is equally transformative. He has diligently built a record of landmark victories in some of British Columbia’s most complex cases:
- Secured one of the largest interim support awards in BC history (Zhang v. Chen, 2023 BCSC 2206, $90M case);
- Convinced the court to reject a Texas custody order on public policy grounds (S.S.C.M. v. A.C.W., 2024 BCSC 1694);
- Succeeded in a 25-day parental alienation trial resulting in parenting enforcement, fines, and court-ordered therapy;
- Overturned final summary judgment in Cho v. Kim, 2023 BCSC 780;
- Prevailed in a 30-day trial involving complex spousal and retroactive child support; and
- Authored a support article cited in Payne on Child Support 2024, a leading national text.
Fraser appears regularly at all levels of BC courts including the BC Court of Appeal and BC Supreme Court, and his reported decisions continue to inspire others and shape the future of Canadian family law.
Vancouver High Net Worth Family Lawyers 604 602 9000
Our award-winning Vancouver ultra-high net worth family lawyers have set multiple precedents, achieving record outcomes for clients includes the highest spousal and child support awards, the largest lump-sum spousal support, significant special costs, and the most substantial fines, penalties, and jail sentences in family law cases involving spouses who defied court orders.
MacLean Law has secured decisions for high net worth family law disputes for over 41 years. Additional awards and accolades include:
- Canadian Lawyer Magazine Leap Canadian Family Law Firm of the Year 2024 nominated three years in a row from 2023-2025
- Top 25 Canadian Lawyers, Fraser MacLean
- Lorne MacLean, KC named Canadian Lawyer Magazine Top 25 Canadian Lawyers
- Business in Vancouver BIV 500 Award, Lorne MacLean KC
- Top Choice Best Vancouver Family Law Firm, 2016-2025
- Best Three Rated family lawyers, Vancouver, Surrey, Richmond 10 years plus
- Top Vancouver Family Law Firm Consumer Guide for multiple years
- MacLean Law has achieved multiple wins in the SCC, BCCA and BCSC courts, establishing precedents for “maximum contact” for children, highest spousal support interim awards, highest spousal support permanent awards, highest special costs awards, Mareva Injunctions across the World, Anton Pillar raid successes, 6 month jail time for catching opposing party on hiding income and assets, highest fines awards, relief in cases of parental alienation and more.
