In the first scene, when James Barrett is arrested by the Department of the Navy security personnel, he is addressed as "Sergeant James Barrett." However, Barrett is a U.S. Navy SEAL, which means that he cannot possibly be a "Sergeant," as this rank title does not exist in the U.S. Navy. (The U.S. Navy equivalent of Sergeant in the enlisted ranks would be Petty Officer Second Class (PO2), equivalent to the E-5 pay grade.)