Character mistake: When McCall put his gun to his head and pulled the trigger, he's saddened that it didn't go off. Most handguns (including the one he was using), after the last round is fired, the slide locks to the rear. He would not have made the mistake of thinking it was loaded.
Character mistake: The end credits (which are also IMDb's source) have the protagonist as "Detective Lucas Boyd." However, in the movie, his name (see the nametag on his desk) is spelled "Lukas" with a K. (01:01:05)