In the past few years, Canadian Courts, administrative tribunal bodies and law societies have rather rushed to adapt to the increasing availability and widespread use of generative artificial intelligence applications such as ChatGPT. This effort to enact guidelines and rules to manage the use of these new tools was undoubtedly, at least in part, a result of the growing number of instances of lawyers in the United States relying on “hallucinated” case-law citations in their submissions.
As 2023 was coming to a close, the Federal Court issued a Notice to the Parties and the Profession on the use of artificial intelligence in court proceedings.[1] Consistent with several other provincial courts, the Notice required parties to inform the Court, and the other parties, if they have used artificial intelligence to create or generate new content in preparing a document that is filed with the Court. If any such content had been included in a filed document, the Notice provided that the first paragraph of the text in that document must disclose that AI had been used.
The Notice also advised that counsel and the parties are to verify any AI-related content – that there was a “human in the loop” – and set out principles to guide the use of AI in court documents, including the use of only well-recognized and reliable sources when referring to legal authority or analysis.
This Notice was further updated in May 2024.[2] It clarified that a Declaration is not necessary where the AI program used lacks the creative ability to generate new content (such as system automation, voice recognition, or document editing), or where it was used to merely suggest changes, provide recommendations, or critique content already created by a human. It also confirmed that the inclusion of a Declaration will not in and of itself attract an adverse inference and that, when taking over a matter from another lawyer or a self-represented litigant, counsel was expected to use best efforts to provide a Declaration in respect of any previously filed materials they have reason to believe may include AI generated content.
More recently, some tribunals have followed suit by issuing their own practice notices on the use of generative AI. In April 2025, Tribunals Ontario issued its Practice Direction on the Use of Artificial Intelligence (AI) in Tribunal Proceedings,[3] which largely mimics that of several Canadian courts, including the Federal Court. A similar practice notice was published in early June 2025 by the Trademarks Opposition Board.[4] The latter comes after two separate instances of hallucinated citations in matters adjudicated by the Board.[5]
In addition to these practice notices, the Ontario Civil Rules Committee went even a step further. Notably, new provisions in the Rules of Civil Procedure were enacted in 2024 requiring that any factum or expert report filed with the Court include a signed statement certifying the authenticity of every authority cited therein.[6]
Despite these measures, there have been cases in the past few years involving “hallucinated” legal citations being relied upon by lawyers. The rulings in these cases reflect the court's commitment to balancing firmness with fairness, while making clear the gravity of such misconduct and the potential consequences.
In February 2024, in Zhang v. Chen,[7] the British Columbia Supreme Court held counsel personally liable for costs incurred by the other party, due to the citation of two fictitious cases that had been imagined by ChatGPT. The successful party asked for special costs, which requires “a serious abuse of the judicial system... or dishonest or malicious misconduct… that is deliberate”.[8] A mere “mistake, error in judgment or even negligence” does not, however, warrant such an order.[9] While the Court does refer to the lawyer’s conduct as being an abuse of process, it ultimately found that the lawyer did not have the intention to deceive or misdirect.
The Court concluded that the lawyer should be held personally liable to pay part of the costs owed by their client to the successful party; this remedy is available where a lawyer “has caused costs to be incurred without reasonable cause, or has caused costs to be wasted through delay, neglect or some other fault”.[10] Costs were allowed for a total of 2 hearing days, as well as any reasonable disbursements. The lawyer was also ordered to review all their other matters before the court to verify whether any materials contained case citations or summaries that were obtained from ChatGPT or other generative AI tools, and to advise the Court and opposing parties accordingly.
In May 2025, a similar issue arose in Ko v. Li,[11] a matter heard by the Ontario Superior Court of Justice, where Applicant’s counsel had submitted a factum citing several decisions that were either non-existent or irrelevant to the arguments and principles they purported to support. Upon realizing that the case law was most likely an AI hallucination, Justice Myers ordered applicant’s counsel to a “show cause” hearing. Justice Myers emphasized the seriousness of these actions, noting that it is a litigation lawyer’s “most fundamental duty” not to mislead the Court.[12] Furthermore, the decision in Zhang v. Chen was distinguished as, unlike in Zhang, counsel in this case did not catch their mistake before the hearing, had not withdrawn their factum before the hearing, had not apologized and had not corrected the mistake prior to the issuance of the Court’s judgment.
Fortunately for counsel in Ko v. Li, the show cause hearing never took place. At the show cause scheduling conference, Justice Myers withdrew the show cause order and deemed it satisfied.[13] Justice Myers did so, in part, because counsel had admitted the facts, apologized and proposed additional positive steps, including an undertaking to complete six hours of Continuing Professional Development in legal ethics and technology. Justice Myers also took notice that counsel had gained a certain notoriety because of their misstep, including through the publication of various articles in both the legal and general press. Justice Myers therefore concluded that the objective of the show cause hearing, including maintaining the dignity and fairness of the civil justice system and denouncing this type of misconduct, had already been met.
While the appearance of hallucinated case citations in Canadian courtrooms and tribunals is concerning, it may not be unreasonable to be cautiously optimistic about the road ahead. As the legal community becomes more attuned to the current limitations of generative AI, and as the consequences of misuse become more apparent, such incidents should remain rare. Although vigilance and education will remain key, the foundation being laid by these developments offers some reason for confidence in the system’s ability to adapt and respond appropriately.
[1] Federal Court, Notice to the Parties and the Profession, “The Use of Artificial Intelligence in Court Proceedings”, December 20, 2023.
[2] Federal Court, Notice to the Parties and the Profession, “The Use of Artificial Intelligence in Court Proceedings”, May 7, 2024.
[3] Tribunals Ontario, “Practice Direction on the Use of Artificial Intelligence (AI) in Tribunal Proceedings”, April 2025.
[4] Trademarks Opposition Board, “Use of AI in proceedings before the Trademarks Opposition Board”, June 4, 2025.
[5] See Industria de Diseño Textil, S.A. v Sara Ghassai, 2024 TMOB 150 and Monster Energy Company v Pacific Smoke International Inc., 2024 TMOB 211.
[6] Rules of Civil Procedure, R.R.O. 1990, Reg. 194, Rules 4.06.1 (2.1) and 53.03 (6.1)
[7] 2024 BCSC 285 [Zhang].
[8] Zhang, supra. note 7, para. 26
[9] Id.
[10] Supreme Court Family Rules, B.C. Reg. 169/2009, Rule 16-1(3); Zhang, supra. note 7, par. 41.
[11] 2025 ONSC 2766.
[12] Id., para. 22.
[13] Ko v. Li, 2025 ONSC 2965.
