Overhealing Question

[bgd624624]

Was in a low level leveling dungeon (Cutter's Cry). All was going well and then the tank started to tell the healer he was overhealing (I was DPS, not the healer).

I understand what overhealing is, and get that it generates enmity... but how does the tank know this? Am guessing he's probably using a 3rd party parser to monitor percentage. Not cool in a low level dungeon, but it is what it is. Can he "see" this any other way? I.e. I guess if he notices that the healer keeps casting heals when his HP is full or near full.