I've had times where someone reports a body and literally just says skip without saying anything else, they get voted off and they weren't impostor.
Then I've called out people alot of times for faking a common task at the start of the game, then people start saying stuff like "visual tasks are off!" or they just act annoyed, then they either vote me off or skip and if they vote me off, they usually just end up losing to the person who I said was impostor.
Then as Impostor, someone once literally gave me out by saying I was with them doing medbay scan, when I was with other people
I don't even have to mention the failed double kills do I?
Oh yeah and this one time, it was 6 people left, I call O2 sabotage, there is like 5s left, I kill the only person who was fixing it, then my Impostor teammate comes, fixes the sabotage, then he immediately goes to the button and calls me out..