This has got to be one of the most meaningless dramas I've ever had the misfortune of opening.
Forum Self Deletes are for trolls, or people who need a reason to not come back (less likely). You're not going to stop trolls, nor people desperately trying to leave the community. In terms of youtube, he's already permabanned, so this topic is only further made useless.
Stop giving trolls attention. The purpose of a forum Self Delete is to get attention, precisely like this topic is giving them. Let them die in silence.