That should never be able to happen, and out of all the playthroughs of people going through it, I don't recall ever having heard of that happen before (Demonaica on the door). So something was really funky with how that generated the room, kind of a freak accident in procedural generation (which can occasionally happen with any game with procedural content). Sorry about that -- if it hadn't pushed you into defeat, we could have altered your savegame file to fix it.