Factual error: The Lockheed 1011 was only produced until 1984. There's no way that in 1999 Toby would be flying on one that "just came off the line 20 months ago."
Factual error: The family stays briefly in a British apartment, however the plug sockets displayed are US standard, not UK.
A New World - S3-E20
Factual error: Connor has been raised since he was a few months old by Holtz, a man with a British accent, in a dimension where there are no other humans. There is no possible way he could have an American accent, yet from the moment of his return he speaks with one.
Suggested correction: The demons in Pylea spoke English with American accents (possibly due to Wolfram and Hart's interference), and in tie-in comics, demons in the dimension Connor and Holtz went to were shown speaking regular English, though these comics were released years later.
Factual error: Dr. Eve Russell seems to be a "jack of all trades" in the medical profession, but it's impossible for her to know everything about every medical condition. When Theresa is going to marry Ethan, she goes and gets birth control pills and takes her first pill the day before the wedding. That night they make love. The next day, the wedding never takes place and Theresa flies off to find Julian. She forgets her second pill and sleeps with Julian. Eve tells her that since she didn't take a pill before sleeping with Julian then the baby is his. Any doctor would know that (and also suggest that) birth control pills are not completely effective until a person has been taking them for at least seven days, and a secondary form of birth control should be used. There's no way that Theresa's just taking 1 pill would protect her from being pregnant by Ethan, and this would still warrant a paternity test.
Heads Of Beef / Klub Katz - S1-E11
Factual error: In "Klub Katz" the captian yells "Iceburg, Iceburg, on the starboard side." But when you see the iceburg and the ship, the iceburg was about to hit the bow of the ship.
Factual error: During Tony's assassination attempt he struggles with one of the "hit men" for control of a pistol. One can see that the pistol does not contain a magazine.This would limit the shooter to 1 shot, providing the pistol is not equipped with a "magazine disconnect" if it is than it can not be fired at all. It seems unlikely that a "hit man" would be so ill prepared.
Factual error: In the final scene where Grace Mayberry's house is raided in Trenton, NJ. a New Jersey State Trooper is wearing a badge on his chest. The NJSP has always worn a triangular shaped badge on their hats.
Sandy's Rocket / Squeaky Boots - S1-E8
Factual error: Sandy's dome is both airtight and watertight to keep any water out of the dome and any air inside the dome. When the rocket, positioned outside of the dome, begins to launch, smoke is coming inside the dome. This shouldn't be able to happen if the dome is airtight and watertight.
Anthology of Interest 2 - S4-E3
Factual error: When human-Bender is dancing in the disco with the two girls there is a fully lit disco ball which manages to cast no light beams on the walls and floor, as they normally do.
Factual error: When Mike is describing his attempted invasion of Paris to the TA officers, he mentions going on Space Mountain at Disneyland Paris. However, Mike says that it happened in 1994, which must be correct, as the officers in an important interview like this would pick him up on the inaccuracy. Space Mountain did not open until 1995.
Factual error: The scenery is set in Berlin, following the 1989 Re-Union of Germany. Only thing is: the guards at the archive building use AK-47s, while after the Re-Union, the East German National People's Army and the West German Bundeswehr (Federal Defense Force) were joined - and the West Germans don't use any AKs.
Factual error: On the Series 3 DVD extra disk, it says that the Doctor's role model is "Patch Adams (Robbie Williams)", but the actor Robin Williams was Patch Adams, not the pop star Robbie.
Factual error: CDR Crighton has on his astronaut flight suit. He is wearing an American flag on his right upper arm. But the flag has the field of stars to his rear. It is a flag designed to be worn on the left arm, not the right.
Factual error: When Nasedo kidnaps Liz, he stops in a gas station to leave the FBI another clue. As he is pulling into the station, the sign above the gas pumps misspells the word "brakes" as "breaks."
Factual error: The group finds an underground sea and there is a flock of pterosaurs flying overhead. The professor identifies the pterosaurs as the missing link between pterodactyls and archaeopteryx. This is not true as archaeopteryx (and other birds) did not descend from pterosaurs but from a branch of theropod dinosaurs.