Continuity mistake: When Desmond and Charlie lure the doorman from the fun house, Desmond hits him with a copper pot and his fez falls off and lands in the middle of the doorway. In the next shot, from inside the building, the fez is nowhere to be seen.
Continuity mistake: Tears appear on the mule's mug between shots just after Harold says "I'm sorry, Professor." (01:12:35)