Factual error: Some Freightliner M2 trucks are shown in 1990. That did not come out until 2002. (01:32:56 - 01:35:20)
Factual error: There is a "Covered California" sign in a window. The referenced health insurance exchange did not exist during the 1990 time setting of the movie. (00:20:58)
Continuity mistake: In the desert digging, the Nova's trunk is open, then shut. (01:42:00 - 01:45:00)
Revealing mistake: Deacon uses "hidden" food to get the dog to come up to him. The "treat" is largely concealed - but the dog's slobber gives it away. The camera shifts after Deacon's hand goes next to the dog's mouth, giving the impression that Deacon is just petting the dog under his neck. (00:06:35)
Deliberate mistake: Denzel Washington never wears a vest (at least during the previews). All deputies are mandated to wear at least a level II vest (most will buy a higher protection vest) whenever performing Sheriff duties. Plus his duty shirt is just plain sloppy looking, way too big for him.
Continuity mistake: The number of garbage bags containing Sparma's possessions vary when being transported in Deacon's SUV. Initially, only a few are visible in the cargo area, then a view shows many more, followed by fewer as Deacon continues to drive. When Deacon got to the site, it didn't look like there were any bags in the cargo area, but he POSSIBLY could have already got rid of them; this wouldn't make sense because there were many holes already dug at the site. (01:51:23)