Worst git f**k up?

I somehow managed to duplicate a half finished feature branch onto every other branch, including master. Which broke CI and prod.

Most result would be: I don't know, but it became broken.

That I've done -- probably trying to commit a Unity project to git, that was a real clusterfuck.

That I've seen -- someone who integrated an enormous feature branch into master using a rebase instead of a merge. Of course there were conflicts and the conflicts didn't resolve cleanly, but we didn't find that out until after launch, because there was no git history of the original feature branch thanks to the rebase.