The Night Dr. Loveless Died - S3-E4
Visible crew/equipment: The arm of the actual carriage driver is visible poking through the back of the carriage, slapping the horse and signaling it when to stop/proceed with a second set of reins, showing the actor in the carriage was not controlling the horse at all.
The Night of the Circus of Death - S3-E9
Visible crew/equipment: While West and Gordon question Mr. Lennox at the Denver Mint, the boom shadow can be seen moving at the upper left of the frame. (00:30:15)
The Night of the Turncoat - S3-E13
Visible crew/equipment: As West is swimming in the water tank that is filled with dangerous sea creatures (Hammerhead sharks, etc.) a modern day (1960's) frogman is swimming behind West in the tank.
