Deliberate mistake: During the cavalry charges, swords are held at shoulder height as they would for charging enemy cavalry, not knee height for charging infantry. This was a deliberate decision in order to have the blades more visible.
Deliberate mistake: After pulling the e-brake in his car (Mustang) and turning completely around during a chase scene, "Driver's" vehicle continues to shift gears as he drives in reverse at high speeds.
Deliberate mistake: When George Clooney is in the restaurant, he sits down at a booth alone. From a wide shot, he sits down and then they show a close up and he sits down again.
Deliberate mistake: The agent is entering the office approaching his desk where a computer sits with the screen on depicting classified material. Computers left unattended go dark after x amount of time. This computer being in a federal FBI building should be logged out of and not open for everybody to see. (00:19:00)
Deliberate mistake: The driver's side mirror would not be able to capture the view of the store that Monique is robbing - the mirror is slightly angled towards the rear of the car, plus Arthur's car is parked too close across the street. (00:00:33)
Deliberate mistake: Before Nathan and Karen jump out of Dr. Bennett's car, Dr. Bennett's car is shown taking a sharp turn (close to 90°) and then speeding down the short but steep road. At a high speed, the car should have reached the level road within a second or two. However, Dr. Bennett talked to Nathan and Karen for a longer period of time. When the next exterior view of the car was shown, it was just reaching the intersection and straightaway. The car should have traveled a much greater distance than shown. (00:44:50 - 00:45:59)