This is a good example of ambiguity not working but becoming a kind of cheat. To a point, the story makes sense, Eddie is a psychopath and petty criminal. The older recluse is sexually attracted to a "bad boy." Eddie is genuinely psychopathic so he has no interest in enacting someone else's rape fantasy.  He might well want to commit rape but that is something different. You can't rape a willing soul so it is perfectly reasonable that he would lead her on and then start a fire and escape while leaving her and Mae to suffocate and/or burn to death.
However, we're told at the end that Eddie could not have escaped and yet his body was not found. Thus, we are supposed to wonder if he truly was a demon or even the Devil himself. But this clearly contradicts the fact that, as a petty criminal, he had spent time in jail and had just been paroled. If a demon had suddenly possessed this bad man, the demon could have disappeared but not the man who was Eddie. Again, the ending is a cheat.