Factual error: When the Ranger trainees first meet Samuel L. Jackson, he's wearing the rank of a Specialist on his collars even though he's a Master Sergeant. Title 18, Chapter 33 of the US code prevents the unauthorized wear of a military uniform (among other things), however this does not automatically correct the mistake since a common misconception is that one slight alteration is sufficient to make the uniform legal. Having the wrong rank on is too obvious of an alteration, especially for anybody who has spent more than a day in or around the Army and would still be punishable by law, if he was dressed in an attempt to fool your average citizen outside of a movie.
Factual error: What's up with Nunez? A female soldier is not permitted to be a Ranger in the US Army, let alone take part in a combat FTX.
Factual error: In the scene after Capt. Osborne shoots Col Styles, a couple of Army personnel ask her three questions then she is allowed to leave. This would never happen. First, she would be interviewed for quite some time and this would be documented (i.e.She would have to complete a written statement). She would have to surrender her weapon for testing and evidence. Mental Health personnel from a military hospital would interview her. Lastly she would be relieved of duty for at least three days. (01:24:10)
Factual error: The Soldiers are members of a unit training to be Rangers. Rangers are a light form of infantry and women are not allowed to be in infantry units in the US Army. Roselyn Sanchez would not have been allowed to be a part of that unit in a traditional infantry role, at best she would be used in a support role to help deal with women and children encountered on the battlefield, but she wouldn't be going through actual Ranger training like the men.
Factual error: Captain Osborn wears a uniform with lieutenant bars on it, not a captain's emblem.
Factual error: Throughout the whole movie, in most of the scenes at the jungle bunker while the rangers are talking to one another you can see condensation from their breaths as they speak. This wouldn't happen in the jungle and at tropical temperatures. So this scene must have been filmed on a studio lot in the states during cold weather and not in the tropics.