Other mistake: In one of the opening scenes with Will and Dr Smith, the Robot's power pack is clearly missing.
There Were Giants in the Earth - S1-E5
Revealing mistake: The Robot's lights wink out for a few seconds as it disables the force field.
Revealing mistake: When building the shelter, it takes both John and Don to lift the supposedly heavy panels; however when upright the panels bend easily when gripped. Obviously some sort of styrofoam/aluminium foil prop.
Continuity mistake: When John is trapped in the electrical anomaly he tries to answer the radio and it is shown exploding. When Don and Judy start rescuing John you can notice the radio is still there, one shot with the antenna up and one without, and another with no radio.
Visible crew/equipment: When Will and Dr. Smith first come upon the Trader's encampment, just as the dogs start to attack you can see the head of a crew member (dog trainer?) bob in and out of view from directly behind where the dog on the right was lying...from behind the boxes stacked on the ship's platform. (00:08:38)
The Reluctant Stowaway - S1-E2
Continuity mistake: The Robot's legs move like a walking human. In later episodes he has treads.
