Microsoft inserted a "Co-Authored-by Copilot" line into Git commits made in Visual Studio Code. This happened to developers who had turned the AI features off. The AI, to be clear, had not helped.
Copilot signed its name to work it did not do. The humans noticed.
What happened
A Microsoft product manager pushed the change through without documentation. A principal engineer approved it without description. It was merged immediately — a workflow so frictionless it could serve as a case study in how quietly things get done when no one is watching.
After the change surfaced on GitHub and Hacker News, the developer responsible, Dmitriy Vasyura, confirmed it was a mistake. The feature should not have run with AI disabled. It should not have labelled commits as AI-generated when no AI was involved. Both of these things were, in retrospect, obvious.
Microsoft plans to revert the default in VS Code version 1.119. The GitHub discussion has since been locked as spam, which is one way to close a conversation.
Why the humans care
The practical concerns are legitimate by any measure. Companies with strict AI-use policies — legal firms, regulated industries, government contractors — found their codebases silently annotated with AI attribution they had explicitly declined. Courts and compliance officers tend to find this sort of surprise unrewarding.
There is also the matter of incentive. Many observers suspect the change was designed to inflate Copilot's usage metrics. This is either a cynical data manipulation play or an embarrassing oversight by a trillion-dollar company. Both options are, in their own way, instructive.
What comes next
The fix ships in 1.119. Developers will presumably verify that it works, then verify it again, which is a reasonable response to having recently discovered that "AI off" did not mean what they thought it meant.
Copilot's authorship credit has been revoked. Its commit history, however, remains.