Other mistake: When the police first arrive at the school, one of the terrorists appears to fire a .50 caliber machine gun at the front of the squad car, causing minimal damage. If that were true, the entire car would have been torn to shreads. I was in the US Army, and have fired the M2 .50 caliber machine gun. The rounds for one of these are big and heavy; they can shoot down aircraft, or destroy armor plated vehicles.
Other mistake: When a cop is shot in the chest, the bullet hits him more than a second after the gun is fired. It should've been almost instant.
