Continuity mistake: When the CSM discovers the bright spot on the carpet, he immediately realises that Mulder's apartment was under surveillance. However, one can notice that soon after entering Mulder's apartment, the CSM looks down at the floor and carpet covered with blood and there is no bright spot. (00:14:00)
Continuity mistake: During the meeting at a horse track, after the CSM says "You need my expertise, " the First Elder raises his head. In the following shot from the other side, he raises it again. (00:21:00)
Redux II (3) - S5-E2
Continuity mistake: Although the subtitle states 12:00 AM, Mulder's watch hands mark 02:35. (00:43:16 - 00:43:39)
Continuity mistake: When the Lone Gunmen speak with Susanne Modeski, in the background there are some cars parked in front of the Stadium Inn. However, just seconds after, when the telephone rings, there is a white truck parked at the entrance. Later on, the cars are back again. (00:38:55)
Continuity mistake: During the shootout in the warehouse, a wedding ring is visible on Mulder's finger. While it's possible Mulder was married before, the Lone Gunmen are shown hacking into Mulder's FBI dossier and Langly reads out that he is single.
The Post-Modern Prometheus - S5-E5
Continuity mistake: Izzy unwraps a peanut butter sandwich and sets it on a bare tree stump as bait for 'the Great Mutato', then he steps away with the others. When we see the Great Mutato hurriedly put it down, a paper bag is suddenly sitting on the stump beside the bitten sandwich.
Continuity mistake: Scully's FBI badge number that she gives to the phone company is different to the one she gives in season 4's "Teliko". (00:02:05)
Continuity mistake: The toxicology report lists the birth date of Mrs. Sim as 6/6/67 which would make her 30, but Detective Kresge says that she is 40 years of age. (00:03:45 - 00:14:10)
Continuity mistake: Mulder says that Scully was abducted and missing for four weeks. In "Duane Barry," the date stamp is given as August, then in "3," when Mulder returns to the X-Files office he turns the calendar all the way to November. Since Scully is returned the next episode after this, she must have been missing for at least 3 months, not 1. (00:06:20)
Kitsunegari - S5-E8
Continuity mistake: How was Modell tried and convicted in 1996 if he only woke up six months ago? Six months before this episode would be at least mid 1997. (00:06:05)
Schizogeny - S5-E9
Continuity mistake: After her father is pulled out of the window, Lisa leans out and there is no glass left on the sill, she even places her hands on it. Later when Mulder and Scully look at it, there is all sorts of jagged edges on the sill. (00:16:35 - 00:20:00)
Kill Switch - S5-E11
Continuity mistake: In the same season episode "Unusual Supects" Fox Mulder's file lists him as Fox William Mulder. The A.I. discovers a similar file but the name is just Fox Mulder.
Continuity mistake: In season 2's "Ascension," Skyland Mountain was a private ski resort, yet here we are told it is a national park. (00:25:10)
Continuity mistake: Uroff-Koltoff Star of Russia in New York Harbor is a completely different ship from Uroff-Koltoff Star of Russia leaving Vladivostok at 17:45. (00:33:10)
The Red and the Black (2) - S5-E14
Continuity mistake: While in the car with Scully, Mulder turns his head aside of Scully towards the side window twice: once when the shot is facing Scully, and just after in the shot facing him. (00:40:25)
Mind's Eye - S5-E16
Continuity mistake: When the policeman passes the phone over to Marty, in the first shot from behind she holds it with two hands, while in the next frontal shot she grabs it with her left hand and then with the right hand. (00:13:20)
Mind's Eye - S5-E16
Continuity mistake: While talking through the jail glass, Marty's face is generally directed straight toward Mulder's face when reflected in the glass, but her head is twisted to the right when filmed from Mulder's side. (00:34:40)
Mind's Eye - S5-E16
Continuity mistake: At The End of this episode when Mulder is talking to Marty through her jail cell, the position of their hands change. In one shot, Mulder's hand is covering hers, and in the next, each of their hands are gripping the cell bars. This goes back and forth a few times. (00:43:00)
Continuity mistake: If the Kernoffs were really devoted Catholics why would they have waited six years to have Dara baptised? (00:00:40)
Answer: As he stated many times throughout the series, Mulder needed Scully to be sober and skeptical. Whenever Scully's skepticism wavered and she started questioning her own rationality, Mulder would try to restore her sense of skepticism, because he needed her to be clear-thinking.
Charles Austin Miller