The DOD (Department Of Defense) would not let them film the opening scene in an Air Force hanger, so the shot was done in at the North Ridge, CA VA hospital, with CGI airplanes added in. The cafeteria and barracks scene was shot there too.
Shortly before the barracks scene, Keith David fell off of a seven foot railing outside the building while the actors were between shots, breaking two ribs and cracking two vertebra. He when on to film the scene in great pain and then went to the hospital afterwards.
'Larry the Cable Guy' is wearing his Christian name on his chest lapel - he should be wearing his surname. However, he has no surname in the movie, he is just Larry, so there couldn't be a surname.
When they show the HMMWV as they leave the landing zone, someone has taped a US flag to the left front side of the HMMWV. The US Flag always goes to it's marching right, so it should have been on the right front side. Any military personal would know how to display a flag correctly.