Plot hole: How could the police miss finding Cybil in the trunk of Michael Zane's car when it was in an impound lot? They would have definitely searched the car if he was found in violation of a federal offence (for carrying the weapons). Even if they didn't do a search, they would certainly have heard the sounds that Cybil would have made from being locked in the trunk.

Factual error: Although you'd have to actually live in Boise to catch the myriad of differences from the movie town, the most glaring is that the movie Boise appears to be a lush rainforest, like Vancouver or Seattle. The real Boise is strictly desert, and you won't find those green interstate medians anywhere near here.

Continuity: During the car chase scene between Courtney Cox with Kevin Costner in pursuit, there is at least one instance where Cox's car has been smashed on the sides, then the very next shot has the sides of the car in pristine condition.