Continuity mistake: The truck stolen by Mulder from the Russian labor camp is Unimog 406. However, during the accident scene, when it comes out of the woods and falls from the hill, it miraculously turns into Unimog 404 model. (00:13:30)
Factual error: The last number on the truck's license plate is "77." On Russian plates the last two/three digits stand for a registration place. "77" is a number for Moscow, but the Gulag is located in Krasnoyarsk region, so the number should be different. Besides, the format of the plate (LDDDDL|DD) is incorrect - the correct one is LDDDLL|DD (L - letter, D - digit). (00:11:05)
Character mistake: Vassily Peskov speaks Russian with a strong accent. This is because the actor who plays Peskov (Jan Rubes) was from former Czechoslovakia.
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