Introduction
The integration of generative AI tools in legal proceedings, particularly in drafting legal documents [2] [4], poses significant risks due to the potential for generating inaccurate outputs, known as “hallucinations.” These inaccuracies have led to the establishment of guidelines by law societies and courts to ensure the responsible use of AI in legal work. Recent legal cases highlight the consequences of relying on AI-generated content without proper verification, underscoring the importance of thorough review and adherence to ethical standards.
Description
Generative AI tools used in litigation present significant risks [2], particularly in drafting legal pleadings [2] [4], where they can produce erroneous outputs known as “hallucinations.” These inaccuracies have prompted guidelines from law societies and courts regarding the responsible use of AI in legal work [1]. Recent cases illustrate the consequences of relying on these tools without proper verification [2]. For instance [2] [5], in Bevins v [2]. Colgate-Palmolive Co. [2], an attorney faced sanctions for submitting briefs that cited non-existent case law and failed to certify AI-assisted research [2], resulting in the striking of their appearance and notification to bar regulators [2]. Similarly [5], in Wadsworth v [2]. Walmart Inc. [2], an attorney was penalized for submitting pleadings with hallucinated citations generated from the firm’s own database [2], underscoring the importance of thorough review and inquiry as mandated by Rule 11 [2]. The court imposed fines and revoked the attorney’s pro hac vice admission [2], emphasizing the need for attorneys to verify AI outputs [2].
In Mid Central Operating Engineers Health v [2]. Hoosiervac LLC [2], an attorney did not verify fictitious citations [2], leading to a $15,000 fine and referral to state bar regulators [2]. The court highlighted the distinction between using AI for initial research and relying on its outputs without verification [2]. A federal magistrate judge in New York also sanctioned an attorney for submitting a brief that included five fabricated cases generated by an AI platform [5], resulting in a monetary sanction and a requirement for the attorney to notify her client [5]. In another case [1] [3] [5], a federal district court in Colorado ordered defense counsel for a high-profile client to explain why sanctions should not be imposed after filing an opposition brief with nearly thirty defects [5], including misquotes [6], misrepresentations of legal principles [6], and citations to non-existent cases [5] [6]. The court expressed skepticism about the adequacy of oversight in the use of AI tools, particularly regarding the lawyer’s claims of having personally outlined and drafted the Opposition [6].
In Benjamin v [2]. Costco Wholesale Corp. [2], an attorney faced criticism for submitting pleadings with multiple erroneous citations but received a relatively lenient $1,000 fine after expressing remorse [2]. The court’s frustration with AI-generated errors reflects a broader trend of increasing scrutiny on attorney submissions [2]. Additionally, the United States District Court for the Northern District of California admonished Yelp for relying on an AI-generated statistic in its antitrust complaint against Google without independent verification [5], emphasizing the need for good faith and evidentiary support in factual assertions [5]. The case of Ko v [1] [3]. Li also illustrates the potential consequences of failing to verify AI-generated information, as a lawyer faced contempt of court for citing non-existent cases and was unable to provide valid citations or copies of the referenced cases [3].
These rulings underscore the necessity for attorneys to read and verify cited cases before filing pleadings [2], adhere to local standing orders regarding generative AI [2] [4], and maintain ethical duties of competence and candor [2]. The responsibility to certify the accuracy of pleadings cannot be delegated [4]. When AI hallucinations are identified [4], attorneys are encouraged to be transparent rather than evasive [4], as this may influence the court’s response [4]. Continuing legal education and firm policies on the responsible use of generative AI can foster a more lenient approach from courts in such situations [4]. The experimental nature of generative AI underscores the need for caution in its application within legal contexts [4], as courts are unlikely to show leniency for AI-related errors [2]. Legal professionals must conduct thorough research and maintain oversight of materials produced by AI to uphold their responsibilities to the court and their clients [1], as reliance on fictitious legal authorities undermines the integrity of the judicial process and can lead to serious consequences [1], including contempt of court [1] [3].
Conclusion
The use of generative AI in legal contexts necessitates a cautious approach due to the potential for significant errors. The highlighted cases demonstrate the severe repercussions for attorneys who fail to verify AI-generated content, including fines [1], sanctions [1] [2] [3] [4] [5] [6], and damage to professional reputations. These incidents emphasize the critical need for legal professionals to adhere to ethical standards, verify all AI outputs [2], and maintain transparency with the court. As AI technology continues to evolve, ongoing education and the development of firm policies will be essential in mitigating risks and ensuring the integrity of the legal process.
References
[1] https://barrysookman.com/2025/05/06/ai-hallucinations-lawyers-understanding-the-risks-ko-v-li/
[2] https://www.esquiresolutions.com/the-sirens-song-of-generative-ai-in-pleadings/
[3] https://www.lexology.com/library/detail.aspx?g=57523021-a9ec-4950-842f-b06157a3a24e
[4] https://www.jdsupra.com/legalnews/the-siren-s-song-of-generative-ai-in-3762963/
[5] https://libguides.law.ucdavis.edu/c.php?g=1386929&p=10257661
[6] https://reason.com/volokh/2025/04/25/apparent-ai-hallucinations-in-defense-filing-in-coomer-v-lindell-my-pillow-election-related-libel-suit/
