I don't understand how healers can handle tanks NOT mass pulling. I'm lucky I leveled my AST all the way to 60 with my BF as the tank because pack by pack... Aspected Benefic and the tank is good for the next 30 seconds for you to DPS. At least with chain pulls you might have to cast 2 healing spells in a row, God forbid. Most dungeons in this game don't even let you mass pull that much in the first place.

Also in regards to just letting them die, do your best and if they die then they're at fault... otherwise the only reason the mass pull failed was because you were being a stubborn brat.