Continuity mistake: During the scene in the mall when the girl is in the dressing room, she keeps putting on more layers of clothing. But as they are shooting different shots she will have a hot pink shirt on, then it is back on the hanger, and then back on again. It switches back and forth many times.
Factual error: At the end of the film, when Duchovny and Jones are on the ladder truck shooting the head and shoulders, they are yelling "go go go". They slide down the ladder and the next shot is the fire truck speeding away. Movie elapsed time 5 seconds. It is a physical impossibility for a fully extended ladder to be lowered, retracted and bedded in a span of less than 4-7 minutes. Even if the hydraulic lines are cut, the ladder would remain upright and not collapse/retract.