Revealing mistake: When making traps, he's harvesting powder from a spent shell (primer has been struck). (01:05:50)
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Revealing mistake: When you see Hutch walking backwards through a doorway firing his gun, you can see an actor in the background in the entrance looking directly at the camera. As Hutch passes past him, he puts his head against a wall and plays dead again. (01:18:32)
Answer: Van Gogh's "Bedroom in Arles".