There are way too many to count, but this one happened last night in Expert.

I am all for tanks doing big pulls. I have my super special regens on AST to keep them up while I Gravity spam. However, if you are going to pull big, POP A FREAKING COOLDOWN. MAYBE TWO. But don't pop any and wonder why you died, or pop ALL OF THEM before you even get to the trash packs. >.>