Continuity mistake: When Oliver Jr. takes the vase off the table, you can see that at the left end of the fireplace there is a block and a ball. In the next shot, the block has disappeared and the ball has moved further down.
Continuity mistake: When Stan and Oliver's two sons are playing near the door of their bedroom, Stan Jr. Breaks the doorknob by pulling it, but when their fathers go up to their bedroom after hearing a noise, the doorknob is now completely fixed.
Continuity mistake: When Stan is about to take his shot during the snooker game, the white ball is near the top right pocket, but a few shots later it is now beside the ball near the top left pocket.