Deliberate mistake: Bill's back is some distance from the middle gap in the curtains, but an exterior view of him hugging Ellen captures their faces as if they are standing closer to the window and the gap in the curtains is wider. (00:32:45)
Deliberate mistake: Blood does - but should not - drain out of deceased Mitch's mouth when he is placed on the couch and his head falls over because Oliver gets up. (00:30:10)
Deliberate mistake: Richard falls (or is pushed) into the lake, and a loud splash is heard. However, as he pulls himself onto the deck, no water drips from him. But there is already a large wet area further onto the deck when the sheriff tosses him. (00:18:05)
Deliberate mistake: Elizabeth will not be able to save Mateo from falling backwards into the fire pit by grabbing his hand or pulling him back after his whole body is suspended over the edge. (01:13:47)
Deliberate mistake: At the end of the car chase with Penguin Batman's car drives upon a ramp at high speed before the explosions occur but his car only appears flying through the air and landing 15 seconds after the explosions. That's quite a long jump. (01:23:33)
Deliberate mistake: When Prince Henry was sitting on the porch, there was snow accumulated all along the inner side of the railing - but the attached perpendicular boards (about 4" high) on the outside should have blocked snow, or that amount of snow, from accumulating there. (00:42:30)
Deliberate mistake: There is one vertical board missing between the other parallel boards, but the upper half of the gap is wider and forms a "V" when Mark is videotaping Jenna (who is on the other side of the fence). The missing board, between two parallel boards, has a uniform width from top to bottom. (00:08:40)
Deliberate mistake: A pot pie in an aluminium pan that just came out of the oven would be extremely hot, but Karen was not only able to tolerate it being shoved into her mouth, she was able to take a bite and hold the hot pie pan in her hand without getting burned. (00:09:44)