The Platoon is in its first hot contact and they take a casualty, the extraction of the casualty is pretty slow, tripping over the stretcher, dumping him by the vehicle and not loading him on. In fairness he was most likely fatally wounded and only instant admission to a fully equipped hospital could have saved him. The trauma of being dragged out of the firing line, stretchered and flown out was too much for his damaged body.
You've got to remember that the people evacuating him wanted him to live but were in a whole world of shock themselves, it would have been many of the NCO's first real contact and even more of the privates.
They did their best for him, wasn't enough but I think it made no difference, the young lad was doomed as soon as he was hit.