Starring: Robert Conrad, Dick Cangey, Ross Martin, Whitey Hughes
The Night of the Poisonous Posey - S2-E7
Revealing mistake: The rectangular openings from which the knives thrown at West will actually emerge are visible on the door behind him. After the knives "land," the rectangles disappear. (00:18:50)
The Night of the Poisonous Posey - S2-E7
Revealing mistake: West and Gordon are supposedly hiding in opposite corners of the ice house, yet each actor is crouching in the same area with the exact same blocks of plastic ice surrounding him. (00:40:30)
The Night of the Avaricious Actuary - S4-E11
Continuity mistake: The letter from the Cyclops Insurance Company that Gordon pulls out of his pocket is folded, wrinkled, and well-worn. In the close up of the same letter West reads, the letter is white, pristine, and not wrinkled or folded.
The Night Dr. Loveless Died - S3-E4
Trivia: Dr. Loveless' uncle's name, "Liebknicht", is, aside from the addition of the letter "k", German for "Loveless".