Quote Originally Posted by 'Bigfish',index.php?page=Thread&postID=183635#post 183635
That sounds pretty normal for freshly starting heroics. The things aren't meant to be your first step once you hit 80, and UP itself can be pretty nasty. I haven't had a chance to look at your armory, so all I can offer is some generic "Get filled out in crafted blues and purples." Titansteel Guardians are amazing, and the titanium spellshock pieces should help as well.
The thing is, at 539 defense, he shouldn't be eating crits so something else is up. His avoidance (miss, dodge, parry) is pretty low but his crit % should be 0 on heroic bosses.

My hanging fruit guesses are a broken piece of gear or you're reading the log wrong. But I seriously doubt either of those are the case.