The Fresh Prince Project - S1-E1
Revealing mistake: When Will staples his Malcom X poster to the wall, the wall bends back and forth for a second or two.
Revealing mistake: When Leland Palmer is locked in the cell he starts screaming and runs headlong into one wall, then the other. The first wall wobbles noticeably on impact, indicating it is being shot on a set.
Somewhere in the World It's Christmas - S4-E15
Revealing mistake: At the end of the episode in the Peach Pit, Nat and the gang are all singing Christmas songs while Nat is playing some of the songs on a keyboard. It is very easy to tell by looking at his hands, Nat is simply miming on the keyboard.
Revealing mistake: When Briscoe and Green investigate the auto yard with the stolen, blue SUV, Briscoe handcuffs the owner. When he cuffs him, he turns him, showing his back and his hands behind his back. You can see the actor isn't cuffed, just holding the handcuffs as he walks. (00:06:35)
Return to Nantucket: Part 2 - S1-E4
Revealing mistake: Carol closes her eyes before Helen throws the pie in her face. There was no way she could have known it was coming because Helen was hiding the pie.