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: In the plane, Mason says that Voller's associates killed three American civilians. But they only killed two: Mandy and Plimpton.
Character mistake: The Captain of the USS Fragasso comes onto the bridge. A Petty Officer says, "Officer on deck," and salutes while looking out the forward windscreen. He should have said, "Captain on the bridge" and not saluted.
Character mistake: When Liam brings up the idea about dressing up like the Monopoly guy at Xander's party, Stella says, "You can never go wrong with a top hat and a monocle." The Monopoly guy actually never wore a monocle.