Factual errors: When wearing uniforms with ribbons, Carter often wears an Army Good Conduct Medal ribbon. Unless he served at least 3 years, (or one year in combat), he would not be eligible for that award since the Marine Corps also awards a Good Conduct Medal.
Factual errors: Sergeant Carter's rank is E-7, or "Gunnery Sergeant." As a Gunnery Sergeant, he would be called either "Gunnery Sergeant Carter", or "Gunny Carter", not "Sergeant Carter."