The Night of the Underground Terror - S3-E19
Factual error: The small round table in West's railcar parlor has a flip-over top, with secret maps hidden on the underside. The wine decanter and glasses all stay attached when it flips. But impossibly, when West turns the tabletop back over at the end, there's a full cup of coffee sitting on it. (00:48:30)
The Night of the Underground Terror - S3-E19
Revealing mistake: After West shoots Major Hazard on the water tower, the falling stuntman lands on a safety cushion that is about a half foot below the ground surface. Further, the next scene cut shows Major Hazard being covered by the tower contents, but Hazard is now lying on the ground surface, not below it like the stuntman.
The Night of the Underground Terror - S3-E19
Factual error: The episode opens in New Orleans during Mardi Gras, circa approximately 1873. We hear a jazz band playing "When The Saints Go Marching In" although the song didn't emerge in a recognizable form until the end of the 19th century. (00:00:19)
The Night of the Underground Terror - S3-E19
Continuity mistake: After the third freeze frame, there is an outside fight. West has a major rip in his pants on the left inner seam from the knee to almost his waist - showing his white underwear during the fight. After the camera shot to Gordon and then back to West, his pants are now miraculously mended in the front and inner left leg area with a new large rip on the pant outer right seam from the knee to upper thigh.