
Plot hole: In a close-up, just as Jack is freed from the hole in the water wheel, we see the axle's circular wood frame with its spinning bars, above and behind him, as he runs the wheel. At the end of this close-up, Jack's happy facial expression gives way to a look of dread, as he supposedly sees an approaching metal bar about to make contact with his forehead. This is impossible, since all bars are spinning behind him. After a close-up of the actual bar, in the next shot as Jack's forehead makes contact, he stands further back and is now at the center of the circular wood frame, so as to be in perfect alignment with those spinning bars. (01:52:40)