Continuity mistake: In the scene where Ellen and Newland are seated in her living room by the fire, we see her take a cigarette holder charm off of her bracelet. Then, the next scene shows a closeup of the cigarette holder charm, and she is again removing it.
Continuity mistake: The two buddies are eating and listening to the exposition news item about the "Zone of Personal Freedom." In the last part of the scene ("Who do you suppose are gonna call to clean that up?" the straw inside Chad McQueen's milkshake keeps swapping position between the middle and the rim of the glass. (00:03:20)
Plot hole: In the scene in the hotel, David sees the victim's head on the floor after the killer left. Later when David is in a hospital bed he is watching TV and the reporter claims that all the heads were in Judd's car. The killer would have had to have gone back into the hotel room to get the head of that victim after David saw it. She would have put it in her bag right away if she was saving them all. The bag was even left behind. (01:12:30 - 01:25:00)