It might be nothing, I haven't tried to reproduce it yet. In any case, great work on the game. I'm impressed that it manages to put the essence of survival horror into a roguelike, and that visual style is so nostalgic!
I've got an almost identical setup to that guy and I've had two crashes in half an hour that both happened when I click something as the game over message appears. No biggie since I already lost but still =P Could be related to the floor switching crash which I haven't experienced myself.