I have re-rolled as an undead priest (currently lvl 18) and joined a random dungeon. During a run in Deadmines, one of the dps chaps (a hunter if i recall) snuffed it and blamed me for not healing, since I was focused on keeping the tank topped up. The DPSer's spam was that I am supposed to heal EVERYONE, whereas from my experience in parties, the healer maintains healing on the tank as priority. Also, my priest is shadow specced, so healing is not optimum and mana does become a small issue during boss fights if the tank is struggling.
So, am I right to let him die or am I wrong to concentrate my healing skills and valuable mana on the main tank?
Last thought - telling the dpser to manage his threat caused him to spam more abuse..