Artificial intelligence seems to be all the rage. However, even with all of the technological advances and shortcuts which may now be available, counsel has an overriding and fundamental duty to not mislead the Court. Justice Myers’ recent decision in Ko v. Li, 2025 ONSC 2766 forcefully affirms this principle, and deals head-on with the issue of the use of AI in materials filed with the Court.

Before Justice Myers addressed the merits of the case in Ko v. Li, His Honour scrutinized the applicant’s factum. Apart from noting that the factum did not contain page or paragraph numbers, His Honour commented that the hyperlink to a specific case led the reader to a different case on CanLII, which dealt with an issue wholly unrelated to the matter before the Court. Justice Myers also found that another hyperlink led the reader to an ‘error page’.

Justice Myers plainly asked counsel whether her factum was prepared by AI, such as ChatGPT. Unfortunately, counsel could not provide a direct response and indicated she would ‘have to check with her law clerk’. Ultimately, counsel was unable to provide the Court with accurate citations to or physical copies of the cases cited in her factum.

Moreover, in reviewing the factum again after a first attendance, Justice Myers found that the factum referred to a case (Johnson v. Lanka, 2010 ONSC 4124) and summarized the decision therein; however, the actual finding in Johnson v. Lanka was the opposite of what the applicant’s factum described it to be. Justice Myers’ further review of the applicant’s factum discovered more cases that were incorrectly hyperlinked or inaccurately described.

Justice Myers concluded that the case before him appeared to be similar to cases in which people have had factums drafted by AI/ChatGPT, some of which have created fake legal citations. Justice Myers aptly stated:

All lawyers have duties to the court, to their clients, and to the administration of justice. It is the lawyer’s duty to faithfully represent the law to the court. It is the lawyer’s duty not to fabricate case precedents and not to mis-cite cases for propositions that they do not support. It is the lawyer’s duty to use technology, conduct legal research, and prepare court documents competently. It is the lawyer’s duty to supervise staff and review material prepared for her signature. It is the lawyer’s duty to ensure human review of materials prepared by non-human technology such as generative artificial intelligence. It should go without saying that it is the lawyer’s duty to read cases before submitting them to a court as precedential authorities. At its barest minimum, it is the lawyer’s duty not to submit case authorities that do not exist or that stand for the opposite of the lawyer’s submission. It is the litigation lawyer’s most fundamental duty not to mislead the court.

In addition, Justice Myers cited further decisions dealing with the use of AI in Court, and referred to a decision by Justice Masuhara, wherein it was held that, “Citing fake cases in court filings and other materials handed up to the court is an abuse of process and is tantamount to making a false statement to the court. Unchecked, it can lead to a miscarriage of justice.”

The Court concluded that it must quickly and firmly make clear that regardless of technology, lawyers cannot rely on non-existent authorities or cases that say the opposite of what is submitted. Justice Myers also ordered counsel to show cause as to why she should not be cited for contempt, which demonstrates the importance and seriousness of this issue. Consider yourselves warned 😊.