Starring: Robert Conrad, Dick Cangey, Ross Martin, Whitey Hughes
The Night of the Fatal Trap - S1-E15
Other mistake: Immediately after the opening credits, West has just finished printing a poster. The poster is still on the printing press and shows what was printed face-up. When he prints the next poster, the image is not showing on the face-up side but on the bottom side when he takes it off the printer.
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 of the Infernal Machine - S2-E14
Trivia: West collides with the cook and sends him sprawling face-down in a huge platter of gelatin. Before racing off again, West quips, "Sorry about that, chef!" This was a winking homage to the 60s spy comedy Get Smart and its bumbling hero Maxwell Smart's famous catch-phrase, "Sorry about that, Chief!" (00:47:30)