Abyssal Zone Bosses unable to die and zone locked

Entered an Abyssal zone (?) and fought the boss down to 75% life and his animations stopped and nothing further happened. I was unable to leave the area until I figured out I was able to glitch through the wall leading to the ladder out of the area. I am a Sunder Gladiator with the bleeding/Maim nodes in the ascendancy. Not sure what else may have contributed to it.

Two screenshots from Steam:

http://steamcommunity.com/sharedfiles/filedetails/?id=1226942463

http://steamcommunity.com/sharedfiles/filedetails/?id=1226945131

Thank you

Same thing with me, had him down to 25% though.
Im a Ball Lightning Poison Decay Special Snowflake :D