Other mistake: When Cat picks up the can of Leopard lager which is invisible to Lister, he shakes it, pops the cap and sprays Lister with foam. The foam is visible but the can remains invisible, and that makes no sense. If we are seeing the scene from Cat's point of view the can and foam should both be visible, and if it is from Lister's then neither should be.
Factual error: At the beginning of the intro, the narrator says that the only way to resurrect a vampire is with a sacred rite that can only be performed once a century when the moon is in the eighth house of Aquarius. In Astrology, the eighth house is Scorpio.
Revealing mistake: Shortly after the fight with Becky, Roseanne asks Jackie to go across the street to get her something to drink, so she can smoke in secret. After Roseanne lights the cigarette and walks near the register, Jackie's plaid coat can be seen in the door's window as she waits for the next scene.
Odd Man Out - S3-E6
Factual error: Near the end of the episode when Kevin and Paul are riding their bikes toward each other before they stop for a brief hello of sorts, Kevin rides past a couple cars parked on the street that were built in the early 1980's. A red Pontiac LeMans and a black Pontiac Grand Prix-both were parked in front of the 1969 Ford Thunderbird.
Peeled Grapes and Pedicures - S1-E6
Factual error: Gracientus threatens to assault Aulus Paulinus by shoving a porcupine up his toga. A Roman in AD 123 (or any European, including the Britons for that matter), would not have had the slightest idea of what a porcupine was. He might threaten him with a hedgehog, but a porcupine? Never.
Piratsy Under the Seas - S1-E1
Continuity mistake: When Jolly Roger hands the map to Dale, the map has either a dark brown border or not depending on the angle. (00:08:30)
Factual error: Teddy says that he hates the stories by Wodehouse about the stuttering Bertie Wooster. However, Wooster only had a stutter in the 1965 TV series "World of Wooster", not in the original stories or in any other adaptations such as "Jeeves and Wooster." "You Rang" is set in the 1920s, and thus 40 years too early to have seen that program on television.