While it is annoying and disrespectful when DDs and healers pulls ahead of the tank, it's also frustrating when the tank pulls only like 3 or less mobs specially when there are AOE DDs (BLM/SMN) in the group. It can be overlooked if the tank is new or undergeared but if not and he's doing it just because he wants to (despite being able to "tank ways more than the average") then he's the one who's being disrespectful to the others.
In the OP's case tho, that healer sucks for pulling ahead without even saying anything at all.