Continuity mistake: If the Kernoffs were really devoted Catholics why would they have waited six years to have Dara baptised? (00:00:40)
Continuity mistake: When Dara walks toward the angel, there is only one car, parked on the right side of the street, but when her father approaches her, there is another car parked on the opposite side of the street. (00:02:50)
Revealing mistake: During the autopsy, right after Scully has the vision of her daughter, the body of Paula Koklos can be seen to move (watch her hands and neck). (00:24:05)
Other mistake: In the police station, Scully looks twice at a photograph of one of the dead kneeling girls, whose eyes should be burned out in the photograph, but they are normal.
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