AWOL (Absent Without Leave) is a term used by the United States Army and Air Force. The Coast Guard, Marine Corps and Navy use the term UA (Unauthorized Absence), a Marine would never use the term AWOL.
Meg behaves in a most inappropriate and unprofessional manner when she interferes between the gunny and his Marines, especially in front of his men, and it's absurd for her to issue direct orders to him about his performance of his military duties, over which she does not have any lawful authority, and about which she does not know squat. Meg is supposed to have learned at least a little bit about the chain of command during her abbreviated orientation in Newport, Rhode Island, where she received her commission, and where she attended the Naval Justice School. In this instance the writers placed Meg in an unfavorable light and an untenable position.
After ordering Gunny Granger to stand down, Lt. Austin's uniform insignia is shown reversed. Her Navy Meritorious Unit Commendation ribbon is also on the wrong side. When Harm arrives seconds later, her uniform is correct. This is due to the entire image being flopped on the screen.