Virtue of the Vicious - S1-E10
Revealing mistake: The first time we see the raid on the senator's room, 2 security guards are shot in the head. The blood spray from the second one emerges a fraction of a second before the gun fires. The second time the raid is played out, everything happens exactly the same way, but this time the spray matches the gunshot. (00:11:10)
Revealing mistake: When Castle is gearing up for battle, it shows a close up of him loading a round in a rifle. In one of the rounds the primer has been fired already. (00:30:50)
Revealing mistake: The flipped ambulance at the beginning of the episode does not have a drive shaft. (00:03:09)
