Invisible House For Sale - S4-E16
Continuity mistake: Throughout this episode, the coat rack behind Major Nelson's front door alternates between having a coat of arms decoration in the middle or nothing in the middle. It seems this episode was filmed while a set change was taking place, since previous episodes feature a hand holding a bell as the center decoration for the coat rack and following episodes feature the coat of arms decoration.
Continuity mistake: In the opening, when Oliver goes to grab Lisa's hand, he moves his left hand. When the camera looks at Lisa, Oliver is reaching with his right hand.
Visit to a Hostile Planet - S3-E2
Continuity mistake: When the guy shoots the Robinson Robot it leaves a big bullet hole on the front. In the next shot we see the Robinson Robot turning around and the bullet hole is gone.