Revealing mistake: When the alien posing as a human is exposed, the OBIT screen shows his "true" alien form while he continues to appear human to the naked eye. The actor in alien costume on the screen copies Jeff Corey's movements, but at one point rather badly shatters the illusion by forgetting to raise his arms when Corey does. (00:47:00)

The Outer Limits (1963)
1 revealing mistake in O.B.I.T. - chronological order
Continuity mistake: When the lab equipment shorts out after the earthquake, the unconscious Major Brothers is lying with his head propped up against the wall. But when Hamilton reaches him in the next shot, he's suddenly lying flat and is nowhere near the wall. (00:21:45)
Andro: Better to die than to sit and watch the world die.
The Forms of Things Unknown - S1-E32
Trivia: Part of Dominic Frontiere's haunting musical score for this episode later became the theme and background music for the TV series The Invaders, a show for which Frontiere served as the primary composer.




