The Night of the Plague - S4-E24
Continuity mistake: The last scene shows the back of the boxcar amid dirt and brown/mustard colored short grass. When Ms. Averi Trent opens the door to meet her fiancé, we see a lush green tree by the door.
The Wild Wild West (1965)
1 continuity mistake in The Night of the Plague
Starring: Robert Conrad, Dick Cangey, Ross Martin, Whitey Hughes
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.
Trivia: Due to the rigorous stunts he performed, actor Robert Conrad would often rip out the seat of his already too tight pants.