Revealing mistake: When the lady throws Sylvester through the window, you can see there is a bump on Sylvester's head before he hits the tree.
Claws in the Lease (1963)
1 revealing mistake - chronological order
Continuity mistake: During the lunch scene at the dump, you can see there is a spoon by Sylvester Junior's plate when Sylvester deals out the food. In the next shot, the spoon has disappeared, and in the shot after that, it is back again.