I've long thought that it was a live possibility that George W. Bush crashed a plane in the winter of 1972--and thereafter (very reasonably) did not want to get back in the cockpit.
But if there is "no way to tell," it is because Bush's files have been vacuumed--in which case that tells us something, no?
Fear that the TANG physical would reveal cocaine use. Yes, that's a theory. But are you saying that he couldn't even stop sniffing for the period needed to get a clean physical? Losing your flight status is such a loss of status among the fraternity of pilots...And going from Deputy Asst' Treasury Sec'y to President of the Keepers Of Odd Knowledge Society, would compare how?