I would venture that primarily it's not about the story itself, but more appropriately staying true to whatever the account the film is based on. There's going to be theatrical latitude taken, it's acting after all... but some things need to be more appropriately portrayed. Case in point, the amount of research and different specific events brought in on BHD that actually happened. The donkey in the middle of the firefight, and multiple other events were actual experiences from the guys on the ground. Washing out the HMMWV's of blood and gore is something recalled specifically by my platoon's weapons squad leader when I was a cherry at 3/75.
I think the acting was great, nothing came across as overly dramatic. It wasn't the small details that got wrong in this movie - they executed that aspect perfectly (or as perfect as possible). It was the story line. It was Pete Berg or whoever was in charge of giving the final ok of the storyline and script that made the deliberate errors.