• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
TechAI

Lawyer admits ‘embarrassing’ mistake after Anthropic’s Claude made up a source in a legal filing—and no one caught it

By
Stuart Dyos
Stuart Dyos
Weekend News Fellow
Down Arrow Button Icon
By
Stuart Dyos
Stuart Dyos
Weekend News Fellow
Down Arrow Button Icon
May 18, 2025, 9:39 AM ET
Anthropic co-founder Jack Clark speaking at The Hill & Valley Forum
Anthropic co-founder Jack ClarkTasos Katopodis—Getty Images for 137 Ventures/Founders Fund/Jacob Helberg
  • Anthropic’s attorney admitted to using an imagined source in an ongoing legal battle between the AI company and music publishers Universal Music Group, Concord, and ABKCO Music & Records. The result of the error was that Anthropic data scientist Olivia Chen was accused of citing a made-up academic report to strengthen an argument. An associate for Athropic’s law firm took the blame, calling it an “honest citation mistake” after the inaccurate material was overlooked during a manual review.

An attorney representing Anthropic—an artificial intelligence company—admitted to incorporating an incorrect citation created by the company’s AI chatbot amid an ongoing legal battle between the company and music publishers, according to a Thursday court filing. 

Recommended Video

The erroneous citation was included in an expert report by Anthropic data scientist Olivia Chen last month defending claims about the company using copyrighted lyrics to train Claude, Anthropic’s large language model. Anthropic is being sued for alleged misuse of copyrighted materials to train its generative AI tools.

Although the citation carried the correct link, volume, page numbers, and publication year, the LLM, known as Claude, provided a false author and title, according to a declaration from Ivana Dukanovic, an associate at Latham & Watkins LLP and attorney of record for Anthropic. 

The acknowledgement comes after a lawyer representing Universal Music Group, Concord, and ABKCO Music & Records claimed Chen cited an imagined academic report to strengthen the company’s argument. While U.S. Magistrate Judge Susan van Keulen rejected the plaintiff’s request to question Chen, van Keulen said it was “a very serious and grave issue,” and there was “a world of a difference between a missed citation and hallucination generated by AI,” Reuters reported.

In the declaration, Anthropic attorney Dukanovictook accountability for the mishap, saying it was “an honest citation mistake and not a fabrication of authority,” according to the filing. 

She said the Latham & Watkins team found the article as “additional support for Ms. Chen’s testimony.” Then, Dukanovic asked Claude “to provide a properly formatted legal citation” for the article, which resulted in the hallucinated sourcing..

Claude did not complete the citation correctly, and the attorney’s “manual citation check did not catch that error,” according to Dukanovic. 

“This was an embarrassing and unintentional mistake,” Dukanovic said. 

Anthropic declined to provide further comment to Fortune. Latham & Watkins did not immediately respond to a request for comment.
This is the latest lawsuit challenging an AI company for allegedly misusing copyrighted materials. Media organizations like Thomson Reuters, the New York Times, and Wall Street Journal have all filed suit against various AI companies for copyright violations.

Join us at the Fortune Workplace Innovation Summit May 19–20, 2026, in Atlanta. The next era of workplace innovation is here—and the old playbook is being rewritten. At this exclusive, high-energy event, the world’s most innovative leaders will convene to explore how AI, humanity, and strategy converge to redefine, again, the future of work. Register now.
About the Author
By Stuart DyosWeekend News Fellow

Stuart Dyos is a weekend news fellow at Fortune, covering breaking news.

See full bioRight Arrow Button Icon

Latest in Tech

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • World's Most Admired Companies
  • See All Rankings
  • Lists Calendar
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Tech

AI godfather warns humanity risks extinction by hyperintelligent machines with their own ‘preservation goals’ within 10 years
AITech
AI godfather warns humanity risks extinction by hyperintelligent machines with their own ‘preservation goals’ within 10 years
By Marco Quiroz-GutierrezMay 12, 2026
51 minutes ago
Girls say AI is a smarter tutor, a funnier comedian, and has better taste than their parents, new Girl Scouts survey finds
AIHealth
Girls say AI is a smarter tutor, a funnier comedian, and has better taste than their parents, new Girl Scouts survey finds
By Catherina GioinoMay 12, 2026
1 hour ago
Greenboard co-founders Dave Feldman and Ed Schembor
Startups & Venturecompliance
Greenboard raises $15.5 million to keep compliance from slowing down business in the AI era
By Jack KubinecMay 12, 2026
1 hour ago
klein
CommentarySoftware
SAP CEO: the AI race is being fought in the wrong place 
By Christian KleinMay 12, 2026
2 hours ago
AI strategy
CommentaryStrategy
Your company already has an AI strategy. You just didn’t choose it
By Tomas Chamorro-Premuzic, Tami Rosen and Darko LovricMay 12, 2026
4 hours ago
The Fed is ‘meaningfully deviating’ from one of the most basic rules for fighting inflation, BofA warns
EconomyMarkets
The Fed is ‘meaningfully deviating’ from one of the most basic rules for fighting inflation, BofA warns
By Jim EdwardsMay 12, 2026
4 hours ago

Most Popular

Forget U.S. debt, China's total borrowing is in 'a league of its own'—much worse and deteriorating faster, analyst says
Economy
Forget U.S. debt, China's total borrowing is in 'a league of its own'—much worse and deteriorating faster, analyst says
By Jason MaMay 11, 2026
22 hours ago
OpenAI CEO Sam Altman says Gen Z and millennials are using ChatGPT like a 'life advisor'—but college students might be one step ahead
Tech
OpenAI CEO Sam Altman says Gen Z and millennials are using ChatGPT like a 'life advisor'—but college students might be one step ahead
By Sydney LakeMay 10, 2026
2 days ago
Microsoft’s CFO admits she joined the tech giant without even knowing her salary—and then missed her first day of work
Success
Microsoft’s CFO admits she joined the tech giant without even knowing her salary—and then missed her first day of work
By Preston ForeMay 11, 2026
23 hours ago
‘This is the way’: Elon Musk endorses Warren Buffett’s famed 5-minute plan to fix the national debt
Economy
‘This is the way’: Elon Musk endorses Warren Buffett’s famed 5-minute plan to fix the national debt
By Jacqueline MunisMay 10, 2026
2 days ago
Current price of oil as of May 11, 2026
Personal Finance
Current price of oil as of May 11, 2026
By Joseph HostetlerMay 11, 2026
1 day ago
Trump Mobile quietly rewrote its fine print to say the gold Trump phone may never be made, a year after taking $100 deposits
North America
Trump Mobile quietly rewrote its fine print to say the gold Trump phone may never be made, a year after taking $100 deposits
By Marco Quiroz-GutierrezMay 11, 2026
16 hours ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.