Would you like an in-game parser?

[Lambdafish]

I've seen more healers let tanks die when they never dps than tanks die to healers dpsing. If the healer dps the adds mostlikely die faster which leads to mitigation and the mitigation are dead adds, so the tank takes no dmg.

In my experience, the reason that this happens is because the non-dpsing healer is not paying attention to anything at all and is watching netflix etc. If a healer is DPSing, they tend to do that in the downtime when they don't need to heal, never letting a GCD go to waste, those are GOOD healers, and the ignorance shown by the previous posters is unbelievable.