Revealing mistake: This 1964 episode is supposed to take place in its own near-future (the late 1960s). But some of the shots in the beginning reveal the use of outdated stock footage. During the parade, there's a close-up of a 48-star US flag, a relic even in '64, as Alaska and Hawaii became the 49th and 50th states in 1959. Old flags are supposed to be burned, and wouldn't have been used for civic events such as ticker-tape parades.
Revealing mistake: Mismatched stock footage puts the Venus-bound Barton in four different spaceships during his journey. We see brief shots of a Vanguard rocket launch, an Atlas missile, a V-2 rocket sequence, and finally, special effects shots of the ship borrowed from the 1950s SF series "Men Into Space." Not one of these vehicles even remotely resembles any of the others.