Continuity mistake: A heavy rain can be noticed in the background, yet Mulder and Scully are dry as a bone. (00:20:00)
Continuity mistake: After the part where the head Kindred woman tells Mulder and Scully "I asked you not to interfere", Mulder leads Scully away. From one camera angle, he is leading her away by the hand. In the same scene, but from a different camera angle, he has his arm around her. When we go back to the first camera angle, he is once again leading her away by the hand. (00:33:10)
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)
Revealing mistake: When Mulder is examining the residue on the mouth of the deceased man in The Beginning, the dead body's right eye twitches.
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.
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