Oh, well I wasn't going to argue with you. I've seen it before because I had a buddy named Arma who did nothing but stunt all day. He found out how to spin warthogs, shade turrets, ghosts, banshees, etc.
I don't have any proof, but I remember him wedging the ghost through the base and all through the map. He kept saying, "Either you help me do this, or I ban you forever." lol.
He wasn't apart of any clan and he never shared his stunts except for his immediate friends. Of course, I forget how to do it now. It's been too long since I've played.