Ok, so I was just playing and this guy was _waiting_ for me to show up. Didn't move, didn't aim, just head shot me. Now this wouldn't be an unusual circumstance for me, but he had done that before a couple of times. So I spectated him (and manhut did too, as he was on Mumble at the time).
I really think he is cheating (weird choppy moves, shooting heads while turning around blindingly fast..).
I may be wrong, though, so if you would be so kind to confirm my suspicions...