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: When Hogarth knocks his face into the tree after running, he has a lot of blood on his face, but in the very next shot, in which he turns around after hearing the giant, the blood is gone.
Answer: It was a laxative to make him go to the bathroom.