Continuity mistake: When Speedy rushes out to take all the cheese in the trap that George and Benny have put out for him he is seen wearing a sombrero; however, for the rest of cartoon he is hatless, repeat, hatless.
Continuity mistake: When Speedy runs to the entranceway of the Casino trap that George and Benny have prepared, the position of the "Girls" that George has painted changes between shots.
Continuity mistake: After George has set up the mouse trap, he and Benny go away and hide and you can see George is holding a bag in his left hand. When we see George and Benny hiding behind a crate, the bag George was holding has disappeared.