Continuity mistake: After Mortimer picks up Elaine and literally throws her out the front door, he locks it to make sure she doesn't just open the door and walk in again. When Aunt Abby goes to open the door for Mr. Gibbs less than a minute later, she doesn't have to unlock it.
Continuity mistake: When Velvet and her mother are sitting and talking in the attic, her mother pours some gold coins into Velvet's lap. Velvet is sitting back on her feet, but a few seconds later, she raises up on her knees to hug her mother. The coins should go spilling everywhere, but we never see or hear them.
Factual error: There's a scene when Barbara Stanwyck hides behind an open door to avoid beeing seen by Edward G.Robinson leaving Fred MacMurray`s apartment. To make this possible the apartment door opens outside into the corridor, which is an elegant solution for this situation in the movie. But in the real world no apartment door would open by swinging into the corridor because this would give a visitor standing there a punch on the nose when the resident opens the door.
Plot hole: Jamiel delivers Ali Baba's ransom note to Hulagu Khan by throwing a knife, and the shocked Khan and his guards look to the window. Since Jamiel does not duck away immediately, he should have been seen and identified immediately, but nothing of that sort happens.
Factual error: At the beginning of the film, just after the credits, there is a definition of the word 'army'. It is claimed to be from the 'Encyclopaedia Brittanica', an obvious spelling error - "Brittanica" should have one T and 2 N's.
Continuity mistake: When the lodger is looking down the stairs at Daisy (who has just been handcuffed as a joke), his body faces the railing in one shot, the wall in the next, then the railing again.
Plot hole: Vic Gordon finds the Black Whip's clothes and puts them on. Then he goes to rescue Barbara Meredith (the real Black Whip). Strangely, her outfit fits him perfectly. In other scenes, he is taller and more muscular than she is. Did she keep several sets of clothes in various sizes, including boots?
Continuity mistake: In the scene where we see school children leaving the building and are going home we see two children go over to the see saw to ride on it. Buffalo Bill is talking to a little girl just outside the doorway and when it cuts in for a closer shot of the girl, you can see in the background there are now four children on the see saw; then again when the little girl starts walking home its back to the original two children who were on the see saw earlier on.
Continuity mistake: When Elmer Fudd picks up the newspaper beside him, you can see that he is holding the paper with his hands whilst looking at the front page, but when we see the newspaper in the next shot, his hands are nowhere to be seen.