Factual error: In the scene at the evacuation hospital doctors are seen administering shocks to Marcus Luttrell (Mark Wahlberg) with paddles. The EKG shows a flatline. In reality, medical personnel do not give shocks for a flatline - a "shock" is to correct Ventricular Fibrillation into a normal sinus rhythm, if you have a systole there is no muscle activity in the cardiac area and a manual shock will not achieve anything.
Factual error: In many shots we see a Marc Lee memorial patch. Marc Lee was killed August 2, 2006. Operation Redwing was June 28, 2005, more than a year earlier.
Factual error: During the final attack on the village by Apache helicopters, they are shown with front-mounted machine guns instead of the 30mm cannon. Apaches are not armed with a front machine gun.
Factual error: Throughout the film, the SEALs are seen wearing Mechanix gloves, but the type seen are the current type. What distinguishes them from older models is the velcro wrist strap. The older models had an elastic, velcro strap, while the newer ones have a reinforced, rubberized velcro strap. The newer type as seen in the film is inaccurate for the time period.