The Reluctant Stowaway - S1-E2
Continuity mistake: The Robot's legs move like a walking human. In later episodes he has treads.
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.