Deliberate "mistake": When Granny uses her solo ski as a snowboard the ski becomes much bigger on its own.

Continuity: In the scene where Red is trying to escape from the dynamite-filled cable car, we see the burning fuse as she climbs out of the car. A moment later we see her climbing up the outside of the car, and the fuse has disappeared. Later, when Grandma causes the car to fall into the river in the nick of time, the fuse is just burning through the window space.

Continuity: Japhet the goat steps on a chair but it disappears in the next shot.