Mazaheri v Law Society of Ontario
Law Society Tribunal (ON) · Jun 12, 2026
What happened in this matter?
The Law Society Tribunal (ON) ordered the respondent to pay $31,150 in costs to the Law Society. The panel determined that the lawyer's irresponsible use of generative AI (Grok) to produce court materials—specifically the inclusion of hallucinated case law and misapplied procedural rules—caused significant, avoidable delays and necessitated additional judicial and opposing counsel resources.
- Why the court cared
- The Tribunal reasoned that the lawyer's failure to verify AI-generated materials constituted a breach of his professional responsibility. The panel noted that the submissions were incoherent, cited non-existent cases, and misapplied procedural rules. The Tribunal determined that the resulting loss of hearing time and the necessity of case management sittings to address the defective filings justified a full costs award, serving as a denunciation of the irresponsible use of AI in legal practice.
- Why it matters now
- This case establishes a clear precedent for cost sanctions in the Law Society Tribunal (ON) for the irresponsible use of generative AI. It underscores that lawyers are strictly liable for the accuracy of AI-generated filings and that failure to verify output can lead to significant financial consequences.
Why this matter is tracked
The Law Society Tribunal (ON) ordered a lawyer to pay $31,150 in costs after he submitted materials produced using generative AI (Grok) that contained fabricated case law and misrepresented procedural rules. The lawyer admitted to using the tool to draft his factum and supplementary factum without verifying the output. The Tribunal found that the lawyer's irresponsible use of AI, which included citing non-existent decisions and misapplying procedural rules to substantive legal issues, caused unnecessary delays and required the Tribunal and opposing counsel to conduct additional inquiries. The Tribunal emphasized that lawyers have a fundamental duty to verify AI-generated content and that such conduct warrants cost sanctions to denounce the misuse of technology in legal proceedings.
This case establishes a clear precedent for cost sanctions in the Law Society Tribunal (ON) for the irresponsible use of generative AI. It underscores that lawyers are strictly liable for the accuracy of AI-generated filings and that failure to verify output can lead to significant financial consequences.
Record details
What the record establishes about AI use
The lawyer admitted to using Grok for research and drafting.
The matter arose from a motion to cancel or vary an interlocutory suspension, followed by an admissibility and bias motion. The Tribunal issued this decision specifically regarding the costs of these motions.
Correction behavior is not separately verified in the current record.
Tracked discrepancy record
4 citation, quotation, or authority issues are recorded in the source dataset.
- Fabricated: Case Law | Applicant cited a non-existent Tribunal decision 'Law Society of Ontario v. Mercer, 2024 ONLSTH 136'; hyperlink actually led to Deokaran (the Mercer decision does not exist).
- Fabricated: Case Law | Applicant cited 'Law Society of Ontario v. Kokavessis, 2020 ONLSTH 49' which does not exist; the link in the factum led to a different decision (Sayers).
- Misrepresented: Case Law | Applicant asserted that 'sanctions were imposed for procedural excesses' citing para 29 of Marusic, but para 29 is a neutral factual statement and does not support the claimed proposition.
- Misrepresented: Legal Norm | Applicant repeatedly invoked Tribunal Rules (e.g., Rules 2.1, 7.7, 11.1) to support substantive legal propositions, though the Rules are procedural and thus were misapplied.
Questions this record answers
- What happened in Mazaheri v Law Society of Ontario?
- The Law Society Tribunal (ON) ordered the respondent to pay $31,150 in costs to the Law Society. The panel determined that the lawyer's irresponsible use of generative AI (Grok) to produce court materials—specifically the inclusion of hallucinated case law and misapplied procedural rules—caused significant, avoidable delays and necessitated additional judicial and opposing counsel resources.
- Why does Mazaheri v Law Society of Ontario matter for legal AI risk?
- This case establishes a clear precedent for cost sanctions in the Law Society Tribunal (ON) for the irresponsible use of generative AI. It underscores that lawyers are strictly liable for the accuracy of AI-generated filings and that failure to verify output can lead to significant financial consequences.
- What does the public record establish about Mazaheri v Law Society of Ontario?
- The record summarizes the outcome described in the linked public source. The recorded document is hosted in the upstream publisher archive. This page is not a substitute for the complete docket, subsequent history, or jurisdiction-specific advice.
- Which source supports this Mazaheri v Law Society of Ontario summary?
- The recorded source is Damien Charlotin case archive. It is classified as publisher document archive; review the linked material and subsequent docket history before relying on this summary.
Related matters
Related by court, jurisdiction, tool, or classified failure pattern. Similarity does not imply the same facts or outcome.