Audio problem: The man changing the flat tire in The Beginning of the episode drops his flashlight. He says "dang it" but his mouth doesn't move.
Audio problem: When Jerry uses the elevator, the voice of the computer reads out the floors as "twenty-third floor, fourth floor, fifth floor" etc, missing out the "twenty-" prefix until the 29th floor. The DVD subtitles list these numbers with their prefix, so this was not intentional. (00:21:10)
Audio problem: The first scene following the intro, when Mulder and Scully step out of the car, Scully says, "I still don't get it" but her mouth doesn't move. (00:02:30)
Audio problem: J.T. Walsh is talking to Mulder and Scully about how smart the inmate was. During this sequence, one of the scenes has very poor audio sync. J.T. Is talking but his mouth doesn't match what he is saying. (00:07:25)
Audio problem: Scully asks the deputy if the vests are necessary and he replies in the same scene. His mouth is way off from his reply. It's likely this is because the show was shown on 4:3 aspect ratio televisions at the time, and he would simply not be visible. Because the show was shot in 16:9, he is very much visible on modern televisions and the mistake is incredibly obvious.
Audio problem: Fellig is confronted by the murderer and you can hear the sound of a switchblade knife opening. When the knife is shown in Fellig's back and later in the evidence bag, however, it is a butterfly knife and not a switchblade.
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