Mind's Eye - S5-E16
Other mistake: When Marty is being transferred and 'sees' herself because the killer is watching her, she should have seen herself viewed through a wire fence, as the killer was standing behind one.
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)
Mind's Eye - S5-E16
Continuity mistake: While talking through the jail glass, Marty's face is generally directed straight toward Mulder's face when reflected in the glass, but her head is twisted to the right when filmed from Mulder's side. (00:34:40)
Mind's Eye - S5-E16
Visible crew/equipment: During the scene of Marty's interrogation there is some dark blue element behind Mulder when he is reflected in the mirror. However, in the frontal scene there is just a plain wall behind him. (00:24:00)
Mind's Eye - S5-E16
Continuity mistake: When the policeman passes the phone over to Marty, in the first shot from behind she holds it with two hands, while in the next frontal shot she grabs it with her left hand and then with the right hand. (00:13:20)
Mind's Eye - S5-E16
Other mistake: Since the apartment was supposedly "turned inside out and upside down, " as Detective Pennock claims, it would be practically impossible that such an obvious place as the shaving blades container not be dug up thoroughly by the police. (00:12:15)
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