A funny bug happened to us today in the new heroic (Trial of the Champions). We had just spawned the Black Knight, when one of the champions (the first boss fight) respawned and attacked us. I had a really good group, so the tank just picked up both bosses and we burned down the extra one.
But then just to prove that he hated us. The boss laid down for a sec, the got up, ran over and jumped on a mount. Let me tell you how hard those guys hit when they are mounted.
Not a big deal, we wiped and started again (this time without the extra guy). However, that was a little strange.