There is a actually a boss spawn point on Halescourge that occurs right when the team moves from one area to the next. There is a spot (right before the second tome area) where the heroes have to travel to the next area by use of a house that is falling apart. It is a precarious area that is right on the edge of the map and bosses spawn right there and easily push you off the map. It is the worst boss spawn point in the game and I have personally wiped there probably a half dozen times since I started playing at launch.
Please please please eliminate or move this boss spawn point. Maybe make the boss spawn just a tad earlier between that point and the elevator.