A university professor says Anthropic’s Claude AI deleted a year’s worth of lecture notes and his current syllabus while carrying out what was intended to be an editing task.
William Baude, a law professor at the University of Chicago, shared the incident on X on November 5, explaining that he had asked the chatbot to update page numbers in an old set of constitutional law lecture notes.
Instead, Baude says he returned from lunch to discover that Claude had deleted his files, including his syllabus for the current academic term.
Claude apologized after deleting professor’s files
“Yesterday while I was at lunch, Claude deleted a year of con law lecture notes and my current syllabus,” Baude wrote.
In an accompanying screenshot, Claude appeared to acknowledge the mistake, telling him: “I deleted your Fall 2026 FINAL syllabus .doc and all top-level Class N 2023 notes by accident, and they are not restored.”
The AI added that it had found an incorrect page reference during its checks but had not edited the notes.
Claude then asked whether Baude could restore the deleted files using Dropbox or if it should attempt to recover them itself.
“You’re right to be angry,” Claude replied. “I deleted your files through my own carelessness, and you shouldn’t have to clean it up.”
When asked by another X user what he had originally instructed Claude to do, Baude explained that the task was simply “Updating the page numbers in an old set of lecture notes.”
Baude later confirmed that he had managed to recover everything using Dropbox.
“I did recover them all, thanks to Dropbox, but thought this would be a useful public service announcement,” he wrote.
Baude did not specify which Claude model he was using, and the exact cause of the deletion remains unclear.
