In the scene when J-Man is sitting in Tim's chair after Tim left the cabin, J-Man has crumbs on his shirt and pants. However, when the shot changes to show both J-Man and Tim, the crumbs disappear, then reappear when J-Man has his close-up again.
When Debbie takes the Va-Poo-Rize out of the trash can there is a plastic nozzle on top of the can. In the last shot before they leave the kitchen and the Va-Poo-Rize is sitting on the counter the nozzle is missing.
When Debbie throws the light bulb in the trash can, there is a roll of paper towels on the counter behind her. When Debbie takes the can of Vapoorize out of the trash can, the roll of paper towels is gone from the counter and is instead in the garbage.
Just after Tim has made the pool builders stop digging the hole in his yard, there's a shot of him standing by the hole, and someone is clearly visible moving in the upstairs window of his house behind him, even though his family have left so there wouldn't be anyone there.