Revealing mistake: During the scene when Ray is by himself in bed, he hears a noise in the hall. He goes to see what's there, and just as he is about to go back to bed he turns the hall light off. The light goes off before he puts the switch down.
Revealing mistake: After the "roll your eyes" scene in the bedroom, Ray walks in the house and says "Hey Hakapoo." If you look in the opened door, you can see Peter Boyle's shoulder and half of his face outside the door. He was waiting for his cue.
Answer: War.
By whom?
Edwin Starr.