So I was in a battleground the other day, stabbing the crap out of Allies, when I popped Cold Blood and went on to crit for the rest of the battle. The buff didn't go away, until I inevitably died. I do not know if this bug would survive past loading zones, but if it did, it would surely increase a Mut Rogues DPS output amazingly.
Here are the factors that I can only assume led to the bug, although I have been unable to reproduce it myself:
1. Mutilate spec, spamming nothing but mutilate (facerolling BGs ftw?)
2. Used disarm on my opponent
3. Got myself disarmed at some point soon after, possibley at the same time (we were punching eachother for a while there)
Theories: Sync-disarm with coldblood up, getting disarmed at point of attack cast with cold blood up
I don't have the fastest computer in the world however so I have been having difficulties testing these two theories.