Quote Originally Posted by MadMilitia View Post
Nope. Happened to my Prot / MW / 3 * MM ( no pet ) comp. About 3 times before I pulled everyone closer to the middle and stayed away from the door.

I think one of my hunters got targeted and must have backed into the door.
Did you use feign at any time? I remember when making my Grimrail video I used feign because I wanted to reset the encounter. Usually that did reset the encounter, but one time it only reset halfway and I got a freebie kill on the cannon/boss.

However even if you did feign, the encounter should still be active from the rest of the characters.
I did this fight many times when learning, and have never had the problem of it resetting without me purposely doing it myself. I've often played the encounter just in the start, close to the door. But I guess I've never stood right on the door.