Revealing mistake: At the very beginning of the scene when the bomb is shown, in the lower part of the screen a moving red spot appears which probably comes from the reflection of the bomb's red diode in the camera. (00:36:50)
Revealing mistake: When Mulder finds the Japanese doctor dead on the floor of the train bathroom, the man's eyes are open. Just before the shot cuts to the girl and boy at the door, he closes his eyes.
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