XBOX 360 version hack or something???

I was playing on Grand Bazzar while in the Alleyway flag on Conquest in the room right beside the flag there was a guy who was invincible and this doesnt mean I shot him one or two times and he killed me so i got mad it was me and my 3 squad members went back there and he was standing still while all four of us were shooing him while he was taking his time to kill us all with head shots with his 1911....he was invincible and by time i got my iphone out to record he left the game.

Has anyone seen or heard of this??

More or less a hack, alot of coders dont share their work so their hack doesn't get detected fast