Sullivan & Cromwell Apologizes: AI Generates Legal Citations

An incident involving the prestigious law firm Sullivan & Cromwell has recently highlighted the potential dangers of using artificial intelligence in the legal field. Andrew Dietderich, partner and co-head of Global Finance and Restructuring at the firm, had to apologize to a federal judge after errors attributed to AI hallucinations were discovered in a court filing.

In a letter dated April 18, Dietderich explained to U.S. Bankruptcy Judge Martin Glenn that the filing contained inaccurate citations and other errors, including AI hallucinations. These "hallucinations" occur when AI tools invent case citations, misquote authorities, or generate non-existent legal sources. "We deeply regret that this happened," he wrote.

A table attached to Dietderich's letter detailed the errors, including incorrect case names and numbers, as well as seemingly fabricated citations. These errors were detected by the law firm Boies Schiller Flexner, representing the creditors, whom Dietderich thanked for their vigilance. Sullivan & Cromwell represented the bankrupt company Prince Global Holdings in this matter.

Dietderich emphasized that Sullivan & Cromwell, a 140-year-old firm employing over 1,000 lawyers, has comprehensive policies regarding the use of AI. However, these policies were not followed, and the errors slipped through the usual review process. He took responsibility for this failure and promised to submit a corrected version of the filing. "I take responsibility for the failure in this regard," he added.

The phenomenon of AI hallucinations is not isolated to Sullivan & Cromwell. Since 2023, false legal citations have become more frequent, as noted by Damien Charlotin, a legal researcher who maintains a public database on these incidents in legal cases. Neither Dietderich nor a representative of the firm responded to requests for comments from Business Insider, and the judge also did not react.