Factual error: All through the movie the commander of the American tank that Ltc. Serling fired on is referred to as "Lt. Boylar" yet in the photo shown of him and Serling he is wearing captain's bars. He is also designated as "Cougar 6." In Army terminology "6" designates a unit commander. Had Boylar been a Lt. his designation would have been either "Cougar 16" or Cougar 26" respectively depending on which platoon he was the leader of.
Factual error: In the opening tank battle, we see oil wells burning in the background as the tanks drive across the desert. We later hear that this battle takes place in Basra, which is in Iraq. The Iraqis surely did not burn their own oil wells during the first Gulf War. They did so when they were in Kuwait.
Factual error: Denzel's tank was actually a Centurion, but apparently dressed up to be an M1A1. The ammunition for M1A1s use semi-combustible cases; that is, most of the case is consumed in the explosion of the propellant. There is only a small base cap that is ejected from the gun, not the entire casing as portrayed in the movie. If Denzel's tank was supposed to be an M1 or M1IP, which would have non-combustible cased ammunition, then they wouldn't have fought any T-72s, as no M1s or M1IPs engaged any T-72s.