Continuity mistake: "11 Days to Zero": A saboteur on an overhead scaffold hastily sprays an X on the top of Nelson's car with white paint. In later aerial shots, the X is composed of 2 perfectly straight, thick lines stretching from corner to corner of the car's roof. No way was that X made in a few seconds with a spray can. (00:03:00)
Factual error: "Invaders": The ship's doctor claims that carbon 14 dating proves the man from the undersea capsule to be 20 million years old. Not likely. Carbon 14 testing can date once-living matter only within the last 70,000 years, and is generally considered accurate only within the last 50,000. (00:23:00)
Deliberate mistake: "The X-Factor": When the helicopter is chasing Nelson's car, re-used footage from a first season show briefly turns the otherwise color episode black and white. (00:24:00)
Deliberate mistake: "The X-Factor": Car-wreck stock footage turns the admiral's 1965 sedan into a much shorter, fatter 1950s model when it bursts into flames and rolls down the embankment. (00:26:00)
Continuity mistake: Throughout seasons 2-4: When the series went to color in the second season, the Seaview was redesigned with only one set of observation windows. But stock footage of the old multiple windows continued to appear for the rest of the series, usually with the film dyed blue.
