Factual error: Skinner says that he could not print the file. However, Scully somehow must have been able to print it in order to give a hard copy to Albert Holsteen for his translation. (00:26:35)
Anasazi (1) - S2-E25
Factual error: It is completely impossible the Thinker has made a digital copy that cannot be duplicated.
Continuity mistake: When the nurse takes off the bedding, the sheet is crumpled, but in the next shot it is suddenly pretty straightened and smooth. (00:02:50)
Unrequited - S4-E16
Revealing mistake: The handle and latch next to the supposedly working intercom on the chain-link security gate entrance to the "White Hand" facility is obviously non-functioning - when the gate is opened it can be seen there are no functional operating parts. (00:08:40 - 00:09:15)
Never Again - S4-E13
Factual error: The first time we see Ed's tattoo, it is supposed to have been freshly done and he even removes the new bandage. However, there is no blood or excess ink on his arm, no redness around the lines, no swelling at all; no way at all that it could be a fresh tattoo.
The Sixth Extinction (2) - S7-E1
Character mistake: When Scully is reviewing part of the translation she has made of the alien artifact, there are four amino acids that she has written: Ademine, cytosine, thymine and guanine. Ademine is misspelled. It should be adenine. (00:23:10)
The Field Where I Died - S4-E5
Continuity mistake: When Scully is searching through the pictures to find Sarah Kavanaugh and Sullivan Biddle, she turns the photographs over and they have a label on them to say who they are. Yet when the shot changes angle to show the photos from the back, the labels have disappeared.
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.
Revealing mistake: When the dad and Charlie are eating their ice cream cones at The Beginning of the episode of the episode you can tell that the ice cream is fake.
Factual error: When Suzanne Modeski retreats to the restroom with a pair of pliers to pull out her tooth, she is only gone for approximately 15 seconds before the gunmen follow her. For a petite woman to rip out a strong, healthy molar from her own mouth (which also had metal prongs Underneath in her gum) would not take so little time, no matter how determined she was. It's also highly unlikely that the lack of anaesthetic would have allowed her to do so without making pained noises.
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