Just stating some facts here....
So he was in a military aircraft, nothing fancy, and a fellow soldier(w/e) murdered him. He died due to a lack of oxygen and was found in a crevasse in Antarctica... Hrm..... my guess is that he knew something that someone didn't want him to know, so they had a "buddy" of his take him out and just kind of push him out of the plane. The "buddy" choked the guy to death before pushing him out of the plane, just in case he might survive the fall (which is highly unlikely but still possible). In the struggle he was hit with a blow dart, which was a dud, and after being pushed out of the plane he landed on a steep slope which he slid down. He finally landed at the mouth of a cave, at which point a "bear" (who aren't native to Antarctica) mauled him and kind of flung his body into a "crevasse." Unfortunately for the bear, his paw got stuck on the soldier's harness, which he happened to wear 24/7, and was dragged down into the "crevasse" as well where he froze. -nods- End of story. xD