I see several movies lately and on some first kills when it looks like a wipe ( usualy when 1-3 people are alive ) bosses tend to die when they have like 500k hp or even when they are at 2% hp, cases I remember now it's sinestra EU First ( http://www.youtube.com/watch?v=Qnc8o...layer_embedded ) and a lot of others.
waren't they supose to die at 0HP like everything else ?
Heroic CHO'GALL dieing with 3.43 Million HP (check HP bellow the map on top left ) - http://www.youtube.com/watch?v=keVnBgp_V_E