Dave, you're fighting a battle that's already been lost. Olwen was banned for deliberately griefing a teammate who annoyed him even after he'd been warned that he needed to control his temper. He's already admitted to it, and refuses to accept that it was wrong.
If he'd rather not play cRPG than accept that the same rules apply to him as to everyone else, and that he can't make up his own, then that's his business.