Bad Medicine - S1-E8
Revealing mistake: Footage of the Diablero standing up after killing the first rich woman is re-used in the killing of the next rich woman, evident by the shot of the same curtains in the background for both murder scenes.
Kolchak: The Night Stalker (1974)
1 revealing mistake in Bad Medicine - chronological order
Starring: Darren McGavin, Simon Oakland, Jack Grinnage, Ruth McDevitt
The Werewolf - S1-E5
Revealing mistake: It is obviously a dummy in a woman's dress The Werewolf throws into the empty swimming pool.
Carl Kolchak: If you want a job done right, you just have to foul it up yourself.
Trivia: Lara Parker, who plays Madelaine the witch in this episode, also played Angelique, the witch in the TV series, "Dark Shadows."