The Sixth Extinction (2) - S7-E1
Revealing mistake: When Scully enters the F.B.I. Building after returning from Africa, she isn't wearing her badge. She'd need it to walk around without being stopped by security. (00:35:50)
The Goldberg Variation - S7-E6
Revealing mistake: Henry's right eye is glass, yet its pupil dilates and constricts respective to the amount of light to which it's exposed.
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