In think here, there is no proof of his NBC status, in fact, he has stated that he was born a dual citizen which, to my mind, makes his birth divided and disqualifies him.
A person should be born NBC with no attachments from any country.
Your opinion does not Constitutional law make. You'll have to point to the clause in the Constitution or the law that defines natural-born citizenship the way you do. U.S. law, not Swiss opinion.