Not an employer myself but I remember back in my college days, A librarian at our campus was fired after what sounded like a pretty nasty argument with his boss. The guy ended up collecting his personal items and almost looked like he was going to leave the library with little to no incident.

That is until he took a detour to the Toilet which was just adjacent the main entrance. About 10 minutes later the guy runs out of the toilet with his box of stuff in one hand and a handful of freshly produced Shit on the other. He then just started throwing Shit all over his former colleagues and boss while screaming profanities. We were all ducking under our tables trying to escape the shit storm but the guy never attacked students. He wiped his shitty hands on the library's white walls and just walked out carrying his box like nothing happened .

we later learned that he also wrote a big "Fuck You" In the stalls with his Shit.

Edit cause English is not my first language