Here is the response from an attorney practicing in the federal courts system to your scenario.
No. The son would be a citizen as a default (under statute). Natural Born Citizen has two conditions that are required to be met: (1) Born in the U.S. Mainland (soil of the U.S. - 50 states) and (2) Born to 2 American citizen parents.
Well, based on this, it would seem, that John McCain is not a natural born citizen either.
As far as any ‘Admiral’ exemption, McCain's father graduated from the Naval Academy in 1931, McCain was born in 1936. His father didn't even become a lieutenant commander until 1942.
So, if your friend is correct, McCain is not natual born either.
????