At Flywheel's detective agency, a wall calendar can be seen displaying a large "8". In subsequent shots the calendar reads "11".
When Wolf, Ravelli and Wacky meet Tommy, Wacky has his right arm by his side. In the subsequent shot, when he shakes hands with Tommy, he has his right hand in his pocket.
When Martha Phelps comes to see Flywheel, he's pretending to talk on the telephone. When he hangs up, he puts the receiver upside-down in the cradle, but in the next shot it's in the normal position.
In Mr. Grover's office, Mr. Grover closes the account book and keeps his
hands on the sides of the book, but in the next shot he has his hands crossed on the book.
After he delivers the record to his fan, Tommy sits down to talk with Joan and crosses his hands on his legs. Next shot he is holding a pencil.
Obvious doubles for the main characters during the finale chase sequence (except for close-ups).
During the chase scene, when Wacky roller skates into the elevator, a store directory posted on the wall is backwards, indicating that the shot has been flipped.
When Wacky is propelled up through the open elevator roof door, the wires pulling him and the outline of his back harness are clearly visible.
When Ravelli takes a photo of Flywheel and Joan in the darkened room, Joan and Flywheel are standing along looking toward the camera. When the developed picture is shown, Joan is being grabbed by Grover and turned away from the camera.
In one shot during the chase through the store, Grovers's boutonniere appears on his right lapel, indicating the film was flipped.
When Wacky ushers in the six "missing" Chinese children, there are actually seven children in the group.