Revealing mistake: When Mr Otto's convoy is seen at the start all 3 trucks are kicking up a dust trail. However is one of the long shots, the first truck is not kicking up a dust trail and the bit of dust that was up in the air has disappeared. (00:05:50)
Revealing mistake: At the shooting range just after Blackburn has reported to duty, a Humvee pulls up and the barrel of the .50 on top is wobbling - it's a rubber prop. (00:12:48)
Revealing mistake: When the Hummvee's are heading back to base with the casualty, there is one shot of an RPG missing the convoy and hitting a person. It is obvious that this person is substituted for a dummy. (00:47:35)
Revealing mistake: During the Humvee convoy's dash to the first crash site, a quick, far-overhead shot shows the column racing down a dusty street, kicking up an obviously CGI trail of dust. The dust billows up from the Hummers, but travels in the opposite direction far faster than the ground below, almost as if a very strong wind is blowing in the opposite direction of the convoy's travel, but everything else in the shot shows the air to be calm. (01:06:00)
Revealing mistake: When the two Delta snipers are approaching the second downed Black Hawk, a Somalian man in a white shirt is shown from behind. Clearly visible is a pack on his back. A few seconds later he is shot by one of the snipers in that exact spot. It's a blood pack. (01:23:45)
Revealing mistake: Just after Jamie 'Smitty' Smith has passed away due to being shot in the thigh, the medic starts CPR. The camera cuts from the medic to Smitty and you can see his eyes move. (01:54:57)
Revealing mistake: While running at the very end, there is a close-up shot where a Ranger lifts his rifle to fire. We see it recoil against his shoulder, and we hear several shots, but he doesn't pull the trigger. His finger lies flat against the gun. (02:04:05)
Revealing mistake: At the end of the movie, where Sgt. Eversman talks to the dead Corporal Jamie Smith about Blackburn, he says he's gonna talk to Smith's parents when he gets home. When Eversman places his hand on the chest of Smith, you can see his eyelids move. (02:14:08)
Revealing mistake: When Josh Hartnett is talking to his friend's body near the end after his friend was killed in action, he touches his friend's chest. You can see the actor jump because he wasn't expecting Josh to touch him or wasn't prepared for it, his eyes even twitch and almost open.
Answer: The answer to this question is quite simple. Whenever any book is put on to the screen things must be glorified in order to catch the eye of a film goer. In movies like this one, heroes, brave men, and down right bad ass characters are what people need to see. If the movie was just like the book, there would be just a whole bunch of equally important characters, which is something very rarely seen in movies. So in short they made sgt Eversmann a main character simply because the movie needed one.
That makes sense but does anyone know why Eversmann was the specific soldier chosen as the focus for the movie?