It is possible to pull only the hunter and not the devastator (not sure of the name, the one with the 2 handed hammer).
If you pull the 2 bosses and run toward entrance, when they loose agro, the hunter stay where he lost agro while the devastator just go away to it’s original position. Making the boss fight very very easy with only 1 boss to kill at a time.
I got this bug while trying to solo it for fun. Needless to say it was easy to solo it with that bug.