I was stalking a lord for a while and got it low health, just about to kill it with critical wounds and then...as soon as i shot my spell he ran into his own spike trap and suicided...
This isn't a problem for me, but it may be for another person, maybe its a bug or something that went un-noticed, but just pointing it out...so you may want to watch out for the traps when in a dungeon and killing a lord.