A Bird in the Head Hurts - S2-E11
Revealing mistake: The problem with Rob's story is that he said he shot the bird with the rifle, but the rifle there that Rob is swinging around doesn't have a hole for bullets to come out of. It's a fake.
A Man's Teeth Are Not His Own - S2-E13
Revealing mistake: When Rob is "playing" the piano none of the keys on the piano look to actually be pushed down. Also when he's scratching his back with each of his hands the notes on that same side of the piano are still played. He's not actually playing the piano. (Except for the last 2 notes or chords). (00:02:46 - 00:03:27)
Revealing mistake: Rob and Laura are both freaking out and panicking in their bedroom when all of a sudden Jerry shows up outside their closed window. Yet Jerry puts his arms in their room, showing it's not an actual window.
Will You Two Be My Wife? - S2-E17
Revealing mistake: While Rob is asking for 2 passes for 3 days in the Captain's office the plant that is outside the "closed window" behind the open blinds has leaves can be seen in between each of the blinds. Which means that the tree isn't actually outside and there is no window, just a window frame. (00:04:40)