I know a few of these guys. Usually I think it's pilot first then med school. Some continue to do both, some drop the flying. I was pretty interested in this myself, but with Obamacare, I don't think med school is worth the effort anymore. Have you discussed that with your son?

There is also a possibility of a pilot going to law school, though to apply to that program one has to be beyond their pilot training active duty service commitment (ADSC).