I think he's a troll on the basis that he always has to have the last word about any sort of conflict, whether its an argument or debate or whatever. He can't help but try to egg his opponent on just a little bit further than they want to go. Whether its just a gentle jab or an all-out assault -- he clearly gets off on getting people to reply to him even after they've given up, gotten bored, or admitted defeat, or whatever.