Wall Street law firm Sullivan & Cromwell has issued an apology to a federal judge after a court filing contained approximately 40 incorrect citations and other errors attributed to AI-generated content. The incident has drawn fresh attention to the risks of using artificial intelligence in legal work.
The errors came to light in a letter sent by Andrew Dietderich, co-head of the firm’s global restructuring team, to Chief Judge Martin Glenn of the US Bankruptcy Court for the Southern District of New York. Dietderich stated that the filing was part of an emergency motion submitted nine days earlier, and that the firm takes full responsibility for the mistakes. He wrote: “We deeply regret that this has occurred. The Firm and I are keenly aware of our responsibility to ensure the accuracy of all submissions.”
The filing was related to a Chapter 15 bankruptcy case involving the Prince Group, which is facing allegations of large-scale fraud, forced labor, and financial crimes. The AI tools generated incorrect case citations and misinterpreted sections of US bankruptcy law. The firm admitted that existing internal review policies were not followed, and the required verification steps failed to catch the errors. Dietderich noted: “Regrettably, this review process did not identify the inaccurate citations generated by AI, nor did it identify other errors that appear to have resulted in whole or in part from manual error.”
The mistakes were flagged by rival law firm Boies Schiller Flexner LLP, which represented opposing parties. Dietderich said he contacted the firm directly to thank them and apologize. Following the incident, Sullivan & Cromwell launched an internal investigation to determine what went wrong and whether additional training or stronger checks are needed.
This case adds to a growing list of legal filings affected by AI hallucinations. According to a database maintained by legal technologist Damien Charlotin, there have been 1,334 incidents of AI hallucinations in court filings worldwide, with more than 900 of them in the United States. Many of these cases involve fabricated citations, and some include AI-generated legal arguments.
Sullivan & Cromwell is one of the largest law firms in the US by revenue and has been involved in high-profile cases, including representing FTX in its bankruptcy proceedings. The firm’s AI-related lapse has raised questions about oversight in large legal operations, especially as AI adoption grows across the industry.
