Revealing mistake: The solid brick wall bends like vinyl when Colonel Malloy touches it.
Night Gallery (1970)
1 revealing mistake in A Question of Fear - chronological order
Starring: Joanna Pettet, Rod Serling, Larry Watson, Matt Pelto
Continuity mistake: The shots of Doran from his left rear shows him a couple feet away from the wall while frontal shots show him backed up against the wall.
Rod Serling: For those of you who've never met me, you might call me the under-nourished Alfred Hitchcock.
Trivia: The scene of the spooky castle on the rocky shore was used in episodes of "Gilligan's Island" featuring Vito Scotti as mad scientist Boris Balinkoff.