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.
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.
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: 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.
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: Considering that the plant is supposed to secrete an acid that burns through Moya's entire outer hull, when we see the outer shot while the gas is igniting, there is a considerable lack of damage. The plant ate its way from outside the ship, directly into the ship's internal vents and tiers, yet from the outside, the ship looks exactly the same as always. Shouldn't it have shown some sort of erosion or hull breach where the plant entered the ship?
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.