The only issue is that it makes you look like a bad tank if you say nothing because these people are just like "why is the tank not flashing or lobbing, or attacking the mob I'm on". They really don't consider the option that the tank had just decided to let you tank it because they are fed up with being blamed for their selfish actions. Again though...if you can pull and kill without dying...then cool, but 9/10 they can't.