Continuity mistake: The plot is based on obtaining 3 music boxes, identical in appearance each playing a slight variation of the same tune. Throughout the movie the variations are highlighted as a message is revealed by listening to all 3 variations. Yet at the beginning of the movie when the boxes are all sold at the same auction, when each box is presented, the tune had no variations.
Continuity mistake: After Bugs shoots the man in the audience for coughing, the style of notes in the music book in front of him changes between shots.
Continuity mistake: The postman hangs his bag to the hook on the wall. By the noise, he knows a split-second in advance that an explosion is about to happen, and ducks. The actor ducks out of view; we are not supposed to notice that once he disappears, film editing inserts the part when the background partially detonates. We however do, because the bag in the foreground changes position in the space of a single frame. (00:05:25)
Continuity mistake: The Cadillac limo changes models at times, also having blackwall or whitewall tires.
Continuity mistake: Johnny and Toby are heading to a frog pond. Johnny stops by a fence and considers taking a shortcut through the pasture until Toby warns him of the bull in the pasture. When the two boys turn around, the fence is suddenly several feet away.
Continuity mistake: When the Wolf tells the plastic surgeon to change the Droopy head back to his own head, he is wearing a hat which disappears in the next shot.
Continuity mistake: When Rocky says his prayers and gets into bed, he has a gun belt around his nightshirt. But when he jumps out of bed after seeing Bugs, the gun belt has disappeared.
Continuity mistake: When the evil scientist locks the door to prevent Bugs Bunny from escaping, the scientist is standing against the door bolt. In the next shot, he is now under the bolt.
Continuity mistake: When the state trooper examines the letter, the is no stamp. However, when Charlie Chan (Sydney Toler) examines the letter, there is a stamp present. (00:43:10)
Continuity mistake: When Tom picks up a telephone book, you can see he is holding the book with both hands, but when we see a close-up of the "Ajax Mouse Exterminators" in the next shot, his hands are nowhere to be seen.
Character mistake: In the "Casey At The Bat" sequence, the narrator says "The score is 4 to 2 with but an inning left to play." However, the scoreboard shows that eight and a half innings have been played, and only a half-inning remains.