A lot of the time, if I see one healer save a run because the other healer was too busy being dead, and I don't comm...it's because they ran out of the duty too fast for me to do it >.>
(The rest of the time, if one healer has to pull the other's weight and I don't comm, it's because I was too busy trying not to die myself to pay attention to which healer was keeping my head above water.)