During Shane Patton's "New Guy Presentation" ceremony, a line of patches is seen on the wall. On of them is a tribute to SEAL Team 3 member Petty Officer Marc Lee. However, Marc Lee was killed August 3rd 2006, over a year after the events of Operation RED WINGS.
Several times during the gunfight, we see Murphy and Dietz's M4s, which are unsilenced, make the noise of Axelson and Luttrell's Mk. 12s which are silenced. Also, the silenced Mk. 12s sometimes make the loud firing sound of the M4s.
When Marcus is at the village, he pulls a piece of metal from his thigh and bites onto a dog tag for the pain. As it changes from frame to frame you will notice in one frame he is not biting the dog tag and then is still biting it in the next frame.
A villager is blown back over a white truck with an orange front side panel at around 1hr 46 mins mark and the same villager can be seen being blown back over the same truck again at around 1hr 47mins.
When the Apache helicopters are hovering over Marcus and the crash sight they show a door gunner leaning out the open right door. Then they show the Apache and it has no right door as it is a two seat helicopter where the canopy opens upwards.
When all four men are covering at the cliff during the firefight and Marcus is checking the condition of his team, they send a smoke grenade so they can escape. A crew member is visible, filming the scene.
The base used for Bagram AB Afghanistan is Kirtland AFB, Albuquerque New Mexico. The large hangers you see in the background were made for B-36 Bombers. No such hangers are at Bagram. In one scene you can see the ATLAS-1 Trestle Site used for Electromagnetic Pulse testing for Sandia Labs. The largest wooden structure made with no metal fasteners, screws or bolts. Given Bagram is a very active military base using a substitute for cost and security was perfectly justified.
After the first time the SEALs tumble down the mountain, there is sudden silence broken only by the call of a blue jay. There are no blue jays in Afghanistan but there are in New Mexico where the film was shot.
When Murphy calls on the sat phone, the Marine that picks up identifies himself as a Sergeant when he is clearly a Staff Sergeant. The Marine Corps is strict about rank structure and this would never occur.
Marcus Luttrell's Navy Seal team were armed with the SIG-Sauer P226 Navy and the Heckler and Koch HK45C, not the Beretta as shown in the movie. The correct gun can be seen in the who's who pictures in the credits.
During the end of the movie Marcus Luttrell is in cardiac arrest and has asystole or "flat lines." The doctors shock his heart to revive him, but this is not the procedure for a flat line. Instead, the should have continued CPR and be given medications. The shock to his heart, in the case, would likely cause more harm than good.
The Chinook helicopters in the actual events were special operations variants known as MH-47s. These models have many visual differences from regular Army Chinooks, including their overall black color, refueling probe and radar. They were also flown only by the elite 160th SOAR. The Chinooks in the film, however, are regular army CH-47s without the above-mentioned features, are painted light green and also have the 1st Cavalry Division's insignia painted on the nose, which wouldn't have been on 160th SOAR helicopters.
Many call signs are incorrect for the events in the film. For example, the Chinook helicopter that is shot down while attempting to rescue Luttrell is called 'Bruno 64' in the film, whereas it was 'Turbine 33' in real life.
During the initial mission briefing, Eric Bana's character mispronounces "Chinook", using a "ch" sound rather than "sh". This is most likely attributable to his unfamiliarity with the word, and his general difficulty speaking with an American accent, as evidenced in his first speaking scene after the morning race (Eric Bana is Australian).
The goof item below may give away important plot points.
Marcus has oxygen administered to him in the helicopter after he is rescued, but the medic neglected to inflate the oxygen reservoir before placing the non-rebreather mask on his face. Any EMT knows to do that.