Yes I would respawn. I do when there aren't mages because if there's only one, or two guys alive and, you have enough time to run back. Plus if he/they die also, the boss heals. Too many times have I been with a group where they die and watch me solo a boss. And Ten to one they'll get a better drop than me.

If its not getting loot, then just have their roll automatically drop to the worst loot possible if they are dead when the boss is killed.