Continuity mistake: In the park, when Pongo tries to get Roger to meet Anita he yanks Roger ahead, and Roger leaves his hat on the bench. In the next shot, when Roger and Anita are entwined in Pongo's leash, Roger is wearing his hat. (00:09:30)
Continuity mistake: In the cabin when they are coming up with the idea to swap places, Susan has on white sneakers in the beginning of the scene when she is on the bed, and Sharon has on the black Mary Janes. Later in the scene, with no time to change shoes, Susan is seen walking around the cabin wearing the black Mary Janes.
Continuity mistake: When the two men are carrying water up to their new cave home (via a home made elevator), one of the men is holding two buckets of water. In the shot where you can see the sea behind them, this man hands the second man a bucket of water, which he takes. In the very next shot, from inside the cave, the first man has both buckets and again hands the other man the bucket of water. (00:48:35)
Continuity mistake: The police that come to the aid of the professor are driving an older Ford when they approach than when they arrive to help. The car is a newer model in the later scene.
Continuity mistake: When Sylvester is pursuing Speedy on his motor bike, Speedy stops at the end of the cliff. But when Sylvester sees the cliff, there is now no sign of Speedy.
Continuity mistake: When Sylvester sees the Daily Bugle newspaper, the front cover headline reads "Police Hunt The Cat." You can see the words THE CAT have nothing around them, but when we see a close-up of the newspaper in the next shot, inverted commas have suddenly appeared.
Continuity mistake: When the Coyote tests his dart bomb, he lights it with a match in his left hand. But when he throws the dart bomb in the next shot, the match that was in his hand has gone.
Continuity mistake: When Sylvester and the dog realise their legs have been connected by a pipe in the junkyard, the position of their feet changes between shots.