Visible crew/equipment: When Brad is showing Mulder and Scully the video tape in his house, you can see the crew reflected off the TV screen. (00:12:50)
Visible crew/equipment: In the scene at the very beginning of the episode, when the camera is going up the stairs, you can make out a man's reflection holding a camera on the stairs.
Visible crew/equipment: After talking to the scientist about his car, Mulder and Scully are talking in front of a door. In the glass of the door is a reflection of a third person.
Deep Throat - S1-E2
Visible crew/equipment: When Mulder and Scully attempt to interview Col. Kissell, as he gets out of his car, you can see a square light reflector screen reflected on the car door. (00:12:37)
Visible crew/equipment: When female Marty gets out of the car for the police officer if you look at the left side of the screen you can see the male Marty actor stood there wearing matching clothing and watching the filming. (00:36:33)
Visible crew/equipment: When Ben Drake is walking in front of the paintings in his office, for a short moment one can see the camera setup and the cameraman reflected off the first painting. (00:01:40)
Visible crew/equipment: Mulder talks to the man from NICAP on the other side of the fence. When the shot is looking at the man, film lights are visible reflected in his glasses. Since he is looking at Mulder, there should be lights on Mulder's side, but there are none.
Visible crew/equipment: Mulder is talking to the computer programmer in the prison. The shot starts on the bars and pulls back. A significant shadow caused by the camera is visible on the right side of the frame.
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