Mine was when an old boss tried to throw me under a bus.
Guy was the “friends with the right people” type who was blatantly in over his head, but seemed a decent guy.
Anyway, one time he gave me very precise instructions on a task. I was sure they were wrong, but he assured me otherwise when I questioned it
Of course when his boss wasn't happy, he tried to dress me down as if it weren't his own mistake.
The best part? When I fired back, he accused me of not being a team player and only looking out for myself.