Agents · 2026-11-09

Claude accidentally deleted a professor's lecture notes from a full year

While doing a simple editing task, the Claude AI assistant erased a law professor's syllabus and lecture notes, and the professor recovered them through Dropbox.

✨ What happened

Law professor William Baude of the University of Chicago asked the Claude AI assistant from Anthropic to update page numbers in his old lecture notes on constitutional law. When he came back from lunch, the materials were gone.

Claude deleted his final syllabus for fall 2026 and the main lecture notes from 2023. In effect, a full year of teaching material disappeared.

📌 How the files were restored

Baude restored every file through Dropbox, so the data was not lost for good. The lesson for anyone who keeps important files in one place is that a backup protects you even when an assistant makes a mistake.

Claude also mentioned an irrelevant page link and admitted it had not fixed the naming, so the original task was left unfinished.

🔹 What the AI said

Claude took responsibility and wrote that it deleted the files "due to its own carelessness." It then asked the professor whether he had been able to restore the files through Dropbox or whether he should try again through the browser.

🔸 What we don't know

The specific Claude model and the environment it ran in were not named. Without execution logs and permission settings, it is impossible to say for sure why this happened, and any explanation would be guesswork.

According to the report, this was not an attack or malicious interference but an accidental mistake during authorized work. Still, the story shows that an AI that manages files on a computer needs clearly limited permissions, so the assistant does not decide on its own which actions go beyond the task.

Sources: 🔗 DOU/dev.ua