Revealing mistake: I'm not sure of the episode, but it is somewhere in Season 7. The family was having dinner while Nicky and Alex were upstairs. When the Tanners were having ice cream sundaes, Jesse decides to bring some upstairs to Nicky and Alex. When he sets them on the table upstairs, you could see that they are props.
Revealing mistake: In the scene where Denise, Derek and Michelle are throwing the frisbee, when Derek catches the frisbee, he quickly looks up at the top of the fence and his arm is way too far up to have the frisbee get to Michelle. It is very interesting that the frisbee just happens to land on top of the fence.