Wtf, this thread turned into a major bashfest. You don't have any proof that he is hacking.
He doesn't have to prove ANYTHING to you. Who are you to try to force him to do that? Leave him alone, or report and let GMs investigate if you're really that determined to find out if he "hacks". Just send a freaking ticket and stop bashing, cuz if you're wrong, you might be the one that gets banned.