Factual error: The alternate version of Scully is identified as an OSS agent, but the OSS did not exist in 1939. (00:34:35)
Continuity mistake: If you watch closely you can see that Mulder runs the key card through the door scanner the wrong way, scanning nothing but plastic. (00:25:40)
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)
Miracle Man - S1-E18
Continuity mistake: In the establishing shot of the courthouse the subtitle reads "Kenwood County Courthouse" but you can read on the building that it is the "DeKalb County Courthouse". (00:15:15)
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: 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: 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: When Mulder and Scully are going to the caravan for the first time, you can see a person walking in the background, but when the shot changes they are no longer there. (00:17:05)
Continuity mistake: Just before he removes it, the foil disappears from Ray's sandwich in one shot, then appears again in the next shot.
Factual error: Scully makes a reference to an F.B.I. field office in Kansas City, however, no such office existed at the time of this episode. (00:13:10)
Continuity mistake: We see Cindy and Teena at the table talking with Eve 7, drinking out of paper cups. Later on, when Mulder picks up a cup from the table, it's made of glass. (00:30:40 - 00:34:30)
Continuity mistake: When Max is trying to escape through Mulder's window, in the first shot, the bottom window is halfway down, but in the next shot, it's fully up. (00:15:35)
Visible crew/equipment: When Scully asks Fox "Do you know what day it is?" the boom mic drops down at the top of the screen. (00:04:50)
The Pine Bluff Variant - S5-E18
Continuity mistake: When the bank manager goes to open the door for the brinks truck containing the robbers, the clock on the wall reads 9:45. When the robbers are taking him back to the vault, a couple of shots of the skull-masked robber shows the clock reading about 9:43.
Factual error: Mulder mentions the USS Eldridge as disappearing from Philadelphia (and later reappearing in Norfolk) "nine months after Roswell", i.e., May 1948. In fact, the supposed incident took place much earlier - in February 1943, according to almost all reliable sources. (00:06:50)
Continuity mistake: When Scully and Mulder first visit John Mostow he says that he drew all the pictures of Gargoyles, which would have been a pretty good act considering he was in a strait jacket and would not have been allowed to have paper and drawing materials anyway. (00:07:30)
Continuity mistake: When the dad is offering the son some ice cream, the cone he offers is a single scoop. In the next shot, as the son takes it, it is now a double scoop. In addition, the scoops change from single to double and back and forth in the next few shots.
Visible crew/equipment: When Scully asks Mulder, "Are you losing it?" the boom mic is at the top of the screen. (00:23:20)
Continuity mistake: When Senator Richard Matheson tells Mulder about the four Japanese Nationals had been murdered, he says that the murders had occurred several weeks ago. But when Mulder brings Scully up to speed a scene or two later, he tells her that someone must have been able to identify the four doctors who were performing the autopsy because they were murdered YESTERDAY. (00:30:05 - 00:33:10)
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