Crit immune != crush immune. I'm a pally tank and I'm also uncrushable, tanking prince without problem. To be uncrushable against a level 73 elite you need 102.4% total mitigation. This meaans...
BLOCK RATING + DODGE RATING + MISS RATING + PARRY RATING
That must equal at least 102.4%. You can calculate your miss rating by hovering over your defense rating in your char tab and seeing "Reduces chance to be hit/crit by blah blah". Take that number and add 5% for the chance mobs already have to miss and you'll have your miss rating; I stopped stacking defense at 505 which put me at around 6 something percent in that tab, so my "miss" rating is around 11%.
Extremity, Prot Pally, Emerald Dream. 103% mitigation omg
BLOCK RATING + DODGE RATING + MISS RATING + PARRY RATING
That must equal at least 102.4%. You can calculate your miss rating by hovering over your defense rating in your char tab and seeing "Reduces chance to be hit/crit by blah blah". Take that number and add 5% for the chance mobs already have to miss and you'll have your miss rating; I stopped stacking defense at 505 which put me at around 6 something percent in that tab, so my "miss" rating is around 11%.
Extremity, Prot Pally, Emerald Dream. 103% mitigation omg