I had a friend whose Macbook Pro started kernel panicking every time he exited emacs, completely reliably. A rather bizarre problem that persisted for months on his device, through some updates, but we couldn't replicate on another machine. Some kind of weird hardware issue? Corrupted software somewhere not detected by integrity checks? No idea. But these days, kernel panics and BSODs tend to originate from odd edge-case problems like that.

(And yes, the joke "but why would you ever exit emacs?" was said many times)