Well, sometimes when I have played with my old clan, a clan member of mine somethimes just turned invisible to the other team, and he didnt do anything. His teammates could see him and so could spectator mode people, but the other team couldn't. So I think sometimes it might glitch, but who knows..

Glitch. You cannot cheat in this way - I mean I'm 99% sure of it, but Pas (who posted earlier) knows a hell of a lot more about this than me and he is sure about it too.

So, yeh. Glitch.