Once in C&C Renegade because I shot a lagger before he moved behind a wall. Because of the networking, he did not die till he was in cover.
I think twice in S4 League. Once for jump attacking twice in a row with breaker. I don't know how the person did not know it could attack that fast when everyone who uses breaker does it.
Another time was of course, a lagger who doesn't understand how the game is networked, and even claimed to not be lagging, and continuously argued that the other 7 people in the room were the laggers, not him.
I forget any other instances.