When Carter is playing darts, he hits the 20 spot. But when he goes to pull the dart out, it's on the bulls-eye.
George says he was a mechanic in the Air Force, yet the insignia on his cap (as well as his friend's cap) is that of a full Colonel (O-6). Mechanics are enlisted personnel.
Near the end, George is given the Purple Heart medal by his friend for his bravery while serving. The Purple Heart is given for injuries sustained while serving. Based upon his description of what happened, George could have been given a Silver Star medal. Since he was not injured, he would not be eligible for the Purple Heart. While technically legal (per a 2016 US court ruling), a veteran would consider it inappropriate to wear an unearned medal; however, having it pinned on while his friend is giving it to him is not the same as wearing it in public.