Continuity: Near the end of the movie, Scully's white Ford Taurus is parked outside, even though it had been wrecked earlier in the film. When Scully comes out of the house, a silver Ford Fusion is parked outside.
Factual errors: In the film, they refer to the Richmond "DA" who appears later. Virginia has no District Attorneys. Prosecutors in Virginia are Commonwealth's Attorneys.
Errors in geography: Though the attacks occur in Somerset, West Virginia, in one scene shot from inside the victim's car, you can clearly see a Virginia State Police Inspection sticker.
Continuity: While driving on a snow-covered road, Mulder collides with a truck equipped with a snow plow. His car's front headlight is visibly damaged. In the next scenes, the damage changes from shot to shot.
Factual errors: Scully and Mulder fly in on a helicopter from their house. After landing and exiting the helicopter the rotor is still turning but Scully's and Mulder's hair remain in place. The rotor wash would blow their hair around, in the next shot you see them walking away from helicopter with the rotor still turning.
Errors in geography: In parts of the movie, you can clearly see snow capped mountains in the background. No such mountains exist in West Virginia.
Continuity: When Mulder's car is attacked by the snow plow, the drivers window is shattered, when the car is pushed over the hill, the window is intact.
Continuity: Dacyshyn abducts his second victim of the movie by sideswiping her car with his snow plow. When Mulder trails him later in the movie, there is no damage to Dacyshyn's vehicle.
Incorrectly regarded as goofs: When Mulder is following the pick up truck to the hide out he scrolls through his phone contacts and highlights what some viewers have claimed is the name 'Gillian', the character Dana Sculley's actual first name. However, it actually says 'Gilligan'.
Factual errors: When Scully and Mulder accompany Father Joe to the scene of the agent's abduction for the first time the sun is rising and the screen reads "Somerset, West Virginia, 5:02 AM". During mid-winter in that part of the country it would still be completely dark for over two hours more.
Continuity: When Mulder finds the snowplow truck after been pushed off the side of the road and looks inside for the tire iron, the snowplow's roof lights are on, as Mulder walks away from the snowplow in the next shot, the roof lights are off.
Continuity: After Fox's car is pushed over by Dacyshyn, the underside is shown, revealing dual exhaust. Later when Scully calls Fox, we see the car again with only a single muffler.
Continuity: Near the end of the movie when Scully visits Mulder's house, scene shows her vehicle (Ford Taurus/Five Hundred) parked in drive. When Scully and Mulder emerge from house and converse next to car, vehicle is a different model (Ford Fusion).