You could always do:
	Code:
		if ($hpevent == 50) {
		quest::emote("shakes with laughter and says, 'You are much stronger than I thought. I give up!");
		quest::modifynpcstat("special_attacks",ABfHG);
    		$npc->WipeHateList();
 Makes him unattackable and will not aggro, its all i used.