Factual error: Mulder calls the dust in Maleeni's van "lycopodium powder" that the Los Angeles Police Department used to collect fingerprints, but the real LAPD uses latent print powder not lycopodium. (00:06:35)
Visible crew/equipment: A mic boom operator is visible on the left hand side of the screen wearing a white t-shirt, beige shorts, and sneakers. He's carrying the boom mic and following Mulder and Scully. You can see him when Mulder and Scully arrive at the "Church of God with Signs and Wonders" for the first time...when Mulder delivers the line "That's funny, I knew a couple Catholic schoolgirls who were experts at it." (00:08:20)
Factual error: When Reverend O'Connor is reading from the Book of Revelation, his Bible is flipped open towards the front. Revelation is the last chapter in the New Testament, so his Bible should have been open towards the back. (00:14:30)
Plot hole: When Scully enters the game room after the game has shut off and the Lone Gunman are there but Mulder is missing. She is told that the only way in/out is from the door she came in. Later we find out that the bay that players use to enter the game is at the other end of the room and not conected to the door Scully used. So how did Mulder and Scully enter the game from the bay when the game was running?
Continuity mistake: In the right shot Mulder picks the dirt with his fingers to the plastic bag, while in the left shot he pours it into the bag from the palm of his hand. (00:06:15)
Plot hole: The subject of the stakeout - the religious man dressed as a female prostitute to 'put the other prostitutes at ease' before trying to 'save' them - is shown when Scully is on the phone telling Mulder about it; the man has a very masculine face, a hairy stomach and is in no way convincing. It's extremely unlikely that such an obvious cross-dressed male would fool such a large amount of people.
All things - S7-E17
Other mistake: The surname on the envelope is "Szczesny" (which is of Polish origin and means "Lucky"), so its pronunciation should be something like "shtcheznhy." However, in the subtitles the surname is written as "Szezesny" and pronounced by Scully accordingly. (00:06:30)
Continuity mistake: Although the subtitle states 08:02 PM at the morgue, the clock in the room shows 08:40. (00:12:40)
Continuity mistake: When Chuck Burks is analyzing the pottery, we can see that one of the pieces has a broken edge. Seconds later, the image shows the piece of pottery with the border preserved. (00:17:12 - 00:18:17)
Visible crew/equipment: In the scene where Scully is performing the autopsy on Micah Hoffman, you can see a shadow of someone moving across the wall behind her. (00:23:35)
Fight Club - S7-E20
Continuity mistake: Scully tells Burt that Betty lived in a blue house and later tells Mulder that she found Lulu, who lived in a pink house. Betty actually lived in the pink house and Lulu lived in the blue one. (00:00:30 - 00:13:25)
Continuity mistake: In this episode, both Mulder and Scully say that the last time they were in Oregon was 7 years ago. A previous episode this season dealt with the Millennium, so we know this episode took place in 2000. So seven years ago would be 1993, the year the show first aired. But in the Pilot episode, the corner of the screen reads their location in Oregon and March 7, 1992. 8 years ago. (00:08:20)
Continuity mistake: When Skinner is stopping Mulder from hitting Krycek, in the back shot Mulder keeps his hand on Skinner's neck, while in the front shot he keeps his hand somewhere else. (00:31:50)
Within (1) - S8-E1
Visible crew/equipment: When Scully is looking at her reflection in the mirror, the camera moves toward her and its shadow appears on the left side of the mirror's frame. (00:02:00)
Within (1) - S8-E1
Continuity mistake: When Scully points out the location of the last time they saw Gibson Praise, she points to the (real) Palo Verde Nuclear Plant, which is west of Phoenix. In 'The Beginning' the plant shown was the (fictional) Rolling Hills Nuclear Plant, 60 miles east of Phoenix. (00:37:30)
Without (2) - S8-E2
Continuity mistake: When Mulder's fall from the cliff is filmed from the ground, one can see that he is wearing white shirt, while earlier and afterwards Mulder is dressed in a grey T-shirt. (00:03:20)
Revealing mistake: When George gets out of the car, one can hear strong gusts of wind produced by the coming storm, but trees and bushes do not move at all. (00:00:50)
Revealing mistake: When the detective speaks with the undertaker, on the left side of the screen the place where the smoke is produced is visible. (00:21:35)
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