Mazaheri v Law Society of Ontario

The record

• TribunalLaw Society Tribunal, Hearing Division, Ontario, which hears the Law Society of Ontario’s regulatory proceedings
• DecisionMazaheri v Law Society of Ontario, 2026 ONLSTH 112, reasons for decision on costs of motions, dated 12 June 2026
• FileTribunal File No. 25H-139, heard in writing
• PanelPaul Aterman, chair; Lubomir Poliacik; Michelle Richards
• AppearancesThe applicant, self-represented. Amanda Worley for the Law Society of Ontario
• BackgroundHis licence was suspended on an interlocutory basis on 12 November 2024 (para 1). A panel imposing an interlocutory suspension has not made a finding of misconduct (para 14)
• The two motionsA motion to cancel or vary that suspension, brought 22 October 2025, and a motion to exclude the Law Society’s evidence and to have the panel recuse itself. Both failed (paras 1 to 6)
• Costs claimedThe Law Society asked for its full costs of $31,150. He asked the tribunal to dismiss the claim, to award $5,000 or less, or to defer it to the panel hearing the conduct application (para 7)
• Order$31,150 to the Law Society by 26 June 2026, with interest at 4 per cent per year on any overdue part (para 86)
• ToolGrok, named by him in his own letter to the tribunal of 30 November 2025 (para 62)
• MisconductNone determined in this decision. The Law Society has filed a notice of application alleging professional misconduct, and another panel will decide it (para 39)

What was filed

The materials were a factum, a supplementary factum, an affidavit and a supplementary affidavit, all dated 14 November 2025 and all filed in support of the motion to exclude evidence and to recuse the panel. All of them were produced using generative artificial intelligence, and the tool was hallucinating (paras 52, 53).

The tribunal gives an example at paragraph 54. The factum cited and hyperlinked “Law Society of Ontario v Mercer, 2024 ONLSTH 136”. The link takes the reader to Law Society of Ontario v Deokaran, 2024 ONLSTH 136, because there is no case called Mercer. Other citations were to decisions that exist but say nothing about the proposition they were cited for, and the tribunal’s own Rules of Practice and Procedure, which are rules of process, were cited as if they stated substantive law (paras 55 to 57).

On 25 November 2025 the panel issued a case management direction, attached to these reasons as Appendix A, with a chart identifying each citation it could not reconcile and the question it had about each one (para 60).

His own letter, and the tool he named

He wrote to the tribunal on 30 November 2025, admitted using generative artificial intelligence, admitted that he had not checked the materials before filing them, apologised, and undertook not to use it in preparing anything further (para 62). The tribunal quotes the letter:

“These errors are entirely my responsibility. They arose for [sic] my over-reliance on generative artificial intelligence tools (in particular Grok) to assist me in researching and drafting the documents while I was trying to manage filing these materials on my own.”

That is the only place the tool is named. The tribunal does not say what Grok did or did not do; it records what he said he relied on.

What the $31,150 is, and what it is not

It is the Law Society’s costs of the two motions, in the amount the Law Society claimed (para 7), ordered payable by 26 June 2026 with interest at 4 per cent per year on any overdue part (para 86).

Most of it does not depend on artificial intelligence at all. At paragraph 78 the tribunal says it would have ordered him to pay most of the costs of these motions even if he had not used artificial intelligence irresponsibly: he was unsuccessful on both motions, the litigation was unduly prolonged, and it was reasonable to expect the Law Society to oppose him vigorously. Then, at paragraph 79:

“His irresponsible use of artificial intelligence is an additional and significantly aggravating factor when we consider his conduct in these motions.”

Paragraph 85 puts the two together and shows exactly what the aggravating factor moved:

“We would have awarded the Law Society most of its costs if the respondent had not used artificial intelligence as he did. However, his submission of false and misleading authorities justifies awarding full costs against the respondent.”

So this is not an AI fine. No part of the order is a penalty for using artificial intelligence, and the tribunal records as a governing principle that the purpose of a costs award is not to punish the licensee (para 12). What the AI misuse changed is the proportion: most of the costs became all of them.

What the decision does not decide

The tribunal is explicit at paragraph 39. Its decision flows from its authority to address conduct that arose in the proceedings before it, which means it makes no determination as to whether he engaged in professional misconduct. The Law Society has filed a notice of application alleging that he did, and a different panel will decide that application. Its role here was only to decide the costs of the motions, taking the materials he filed into account.

The first time it happened here, and what it cost the process

“As far as we know, this is the first time that a party has included ‘hallucinated’ authorities in arguments before the Law Society Tribunal.”

That is paragraph 35. Paragraph 75 sets out what followed: the panel had to find out the extent of the problem, document it, give the parties an opportunity to comment on what it had found, and then decide what to do with the materials before the motions could go anywhere. Scheduled hearings were cancelled and two case management sittings were needed to deal with the defective materials (para 77).

Sources

• Mazaheri v Law Society of Ontario, 2026 ONLSTH 112, reasons for decision on costs of motions, 12 June 2026, thirty-four pages including Appendix A, the copy read in full for this page
• The Law Society Tribunal, the body that decided the motions

Related

• The full sanctions record
• SRA v Kumar, the other disciplinary tribunal on this record to deal with a lawyer’s use of AI
• Ko v. Li, the Ontario Superior Court matter whose summary of a lawyer’s duties this tribunal quoted (para 71)
• Zhang v. Chen, quoted by this tribunal on what citing fake cases amounts to (para 72)
• Verification is becoming a duty. Evidence of verification is the missing layer.

Verified 17 September 2026 against the decision, read in full. Information, not legal advice, and not advice on Ontario law.