Revealing mistake: At the end of the film, the screw is tapping on the window to get out and Hogarth moves to put the box down. The box completely vanishes from the shot for a few frames towards the end of the shot.
Continuity mistake: The first time Manley looks at the BB gun, the name on the stock reads "HOG HUG." After his car disappears, he picks up the BB gun again, and now part of the A and part of the H is visible, and the G in the surname is now black rather than brown.
Answer: Turn back to/from what? Can you please expand on the question so we know what you're referring to?