I managed to crash Finder while copying files from one network drive to another. Finder displayed an error message … which I forgot to capture. Finder then stayed stuck on this screen until I killed it.

At least when Windows craps out during a file copy, the copy dialog goes away without having to kill the Explorer process.
The really crappy thing was that it happened at the end of an hours-long file copy operation.
If it happens again, I’ll be sure to get the error dialog.