It sounds a great story and he is probably a terrific guy. However, the pragmatist within says give him a workout but it's highly unlikely that he has the hands to make it in the NFL and meet our TE needs. Army teams for the past 13 odd years have been not just bad, they have been consistently disgraceful and they have only run the ball. If they had a 6'9" weapon who could genuinely catch, he should have been able to make a decent impression on the field.
I'm 99% certain he would be a dud on the field. However, if there is a decent job going within the Dolphin organization, I'd encourage him to compete for it. The West Point education means that he is intelligent and very high character, and the experience in Afghanistan probably means he is well disciplined, can take orders and work with some difficult people. Good luck to the man. He's already a winner in life.