I consider it a very important part of my job as a DPS/tank to make the healers' lives easier in any way I can. If a tank consistently gets hit by avoidable damage, he's making your life very difficult and anyone trying to blame you for the inevitable wipes is a moron. This will happen, and even worse, people with short tempers make situations like this a lot worse. Not much we can do about it except votekick and report if the insults become a problem.