Revealing mistake: Season 2, episode 2 "Virtu-Date": When Pim is jumping rope with the girl, she is building a card house. When she jumps you can see the tape holding it together.
Revealing mistake: In the episode where Phil tries out for the gymnastics team, when he is on the bar you can see it's not Phil, and "Phil" has those special gymnast gloves on that disappear when he dismounts.