Unrequited - S4-E16
Revealing mistake: The handle and latch next to the supposedly working intercom on the chain-link security gate entrance to the "White Hand" facility is obviously non-functioning - when the gate is opened it can be seen there are no functional operating parts. (00:08:40 - 00:09:15)
Unrequited - S4-E16
Continuity mistake: When Scully and Mulder run away from the dogs, the gate is fully open, while in the previous and next shot only the door is open. Plus their car standing in front of the gate is missing. (00:09:30)
Unrequited - S4-E16
Deliberate mistake: When Mulder is about to go into the metal detector he puts his gun on the counter. He goes through the metal detector on his cell phone but his keys set it off, when he steps through again it doesn't go off. No cell phones can go through metal detectors without setting it off.
Unrequited - S4-E16
Factual error: By its uniforms, rank insignia (i.e. point-down chevrons), drill and instrumentation (e.g. tubas instead of sousaphones), the military band performing at the re-dedication ceremony at the Vietnam War memorial in Washington is a Commonwealth (probably Canadian) band and not an American band. Unlikely at a formal military ceremony in the United States.
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