License plate changes for Lewis Parma's car during the drive to the warehouse at the end.
In the tape scene the reels on the tape recorder are of different sizes. Initially the tape feeds from a large core reel to a small-core take-up reel, in the second and third shots, the reels are switched (the large core reel is the take-up reel). In the final (self-destruct) shot, the reels are back to a large-core supply reel, and a small-core take-up reel.
The calendar for November 1971 shows the 1st as falling on a Friday. November 1st, 1971 actually fell on a Monday. The month shown was really for November 1968, the month the show was originally broadcast.
Jim asks the electronics store clerk if he has a 30 rpm (revolutions per minute) tape recorder. Tape machines operate at ips (inches per second) and no consumer tape recorders at that time operated at a speed greater than 15 ips.
The phrase Jim uses is a code phrase. Code phrases are often things that no one else would say. This ensures that when Jim says the phrase to the clerk in the electronics store, the clerk knows he is the right person to give the tape to, since no one else would ever ask for a 30 rpm tape machine.
The phrase Jim uses is a code phrase. Code phrases are often things that no one else would say. This ensures that when Jim says the phrase to the clerk in the electronics store, the clerk knows he is the right person to give the tape to, since no one else would ever ask for a 30 rpm tape machine.
Cinnamon is sitting next to a lit lamp while she is sewing. When Barney turns the projector on the lamp is still lit, but when the projection of her sewing is viewed from the outside, the lamp is off.
Vic often watches events in the next room reflected on the face of the wall clock. But there's no consistency between his vantage point and what part of the room is being reflected.
The wording "Pressure Gauge" looks hand printed on the face of the gauge in the execution chamber.
In the fake death-row room, Barney goes to the door on several occasions and opens the peephole before letting someone in. But he never looks through the hole in such a way as to actually see the face of whoever is on the other side.