A Sullivan & Cromwell partner has apologised after AI hallucinations were included in a motion filed in a federal court in New York.
In a letter sent on 18 April to Chief Judge Martin Glenn at the US Bankruptcy Court for the Southern District of New York, Andrew Dietderich, founder and co-head of S&C’s global restructuring group, acknowledged and apologised for the error.
‘We sincerely regret the errors in the Motion and the burden they have imposed on the Court and the parties,’ said Dietderich.
Dietderich added that he had also apologised to the team from Boies Schiller Flexner representing the opposing clients, after they had initially spotted the errors.
In total, S&C noted 21 inaccuracies in the motion, some of which it attributed to hallucinations. Dietderich catalogued and included the errors in an appendix to the letter. One of the errors appears to be an inaccurate Westlaw identifier relating to the 2022 liquidation of Three Arrows Capital. The inaccurate identifier was included three times in the original motion.
The firm is acting for the joint provisional liquidators of 30 British Virgin Islands-incorporated entities associated with the Prince Group in Chapter 15 proceedings. Alongside Dietderich, the New York-based team includes national security practice co-head Sharon Cohen Levin, corporate governance litigation practice co-head Jake Croke, restructuring partner Aleza Kranzley, and litigation partner Chris Dunne.
The filing follows the indictment of Chen Zhi, the controlling owner of the Prince Group, in October last year. He is alleged to have directed forced-labour scam compounds in Cambodia where trafficked individuals carried out ‘pig butchering’ cryptocurrency frauds that stole billions from victims globally.
While it is not known which member made the error, Dietderich took responsibility for the error on behalf of the S&C team. ‘The Firm and I are keenly aware of our responsibility to ensure the accuracy of all submissions including under Local Bankruptcy Rule 9011-1(d),’ he added.
He further noted: ‘the Firm’s policies governing AI use are both clear and rigorous. Access to AI tools is conditioned on completion of mandatory training. Before any Firm lawyer is granted access to generative AI tools, the lawyer must complete two required training modules, completion of which is tracked and verified.’
‘The Firm is also evaluating whether further enhancements to its internal training and review processes are warranted,’ he concluded.
The apology will be seen as embarrassing for one of the world’s most prestigious and profitable law firms, with $6.74m in profit per equity partner in last year’s Global 100 ranking, and more than $2bn in revenue.
For its part, Boies Schiller Flexner has also included AI errors in a case citation in the recent past, in a 2025 civil case relating to the actor Danny Masterson, who was convicted in May 2023 of raping two women. In a filing in a California appeals court, John Kucera, then a partner at the firm, said he was ‘embarrassed by and very much regret these errors’ in a motion acknowledging that a filed response brief from the firm contained ‘material citation errors’ linked to use of AI.
Kucera left BSF in March, and is now an assistant US attorney for the Northern District of California at the US Department of Justice.
Sullivan & Cromwell has been approached for comment.
Photo: Unsplash – Jason Briscoe

