The Barbarian Sublimation - S2-E3
Revealing mistake: When Sheldon gets the sword for Penny in the game, Penny walks out and you can see the laptop isn't switched on. (00:07:55)
Revealing mistake: When Victor is opening the padlock, sparks fly around in close ups. In the wide angle shots there are no sparks at all.
Revealing mistake: In the wizards versus werewolves special, it's painfully obvious Juliet is a stunt double when she fights and grows her wings.
Chuck Versus the Gravitron - S2-E8
Revealing mistake: In the scene where Ellie is testing her Thanksgiving turkey by giving Morgan a piece, when she throws it in the trash he says 'no no no Sarah.. what are you doing!', which is the actor's name (Sarah Lancaster), not her character's. Maybe edited in some versions. (00:09:40)
Revealing mistake: After Sam shoots Spencer with her blowgun, she lands on the ground after jumping from the ceiling. During this shot, you can easily see that it is a stunt double.
Episode #1.1 - S1-E1
Revealing mistake: When Michael sets fire to Madge's magazine, you can see that the flame was not directly coming out of the lighter. The effect was added in during post-production. (00:05:15)
Revealing mistake: When Copper is talking to Sam in the lobby, Cooper pulls out his phone to cancel his lunch date with Charlotte for that same day and his phone is time stamped as 7:35pm. (00:16:25)
Revealing mistake: The crane in the garden is behind the tree, but we see just the top of it - and under it is nothing.
Revealing mistake: When the couple is breakfasting in Brooklyn their mugs are empty.
Revealing mistake: When mini is in the bath at the start of the episode you can see the bandeau she is wearing in the bath when she lays back down in the tub, probably to stop her being exposed.
Revealing mistake: When "Alice" drinks the potion and hands it to Nostalgia Critic who also then drinks it, the cap on the bottle is still on it. (00:01:20)
Episode One - S1-E1
Revealing mistake: When Gavin and Stacey meet, look at the people all around them in Leicester Square - many of them are stood watching the filming.
Revealing mistake: When Clara is filming her kids, we see her daughter operate the car. When she's supposed to have put the car in gear and have driven forward, you can see the scenery move in the background, showing that the car was stationary and the camera was just violently moved to the right to simulate the act of the car moving.