Not to throw cold water on the story but maybe the story was a bit embellished.
I was an enlisted man in the Marine Corps Air Wing from 1967 to 1971 and all of it was in helicopters. I spent a year at Marble Mountain in Viet Nam. My MOS was to pack parachutes (choppers back then did not carry them) and take care of the pilots gear. I spent part of that year as a door gunner on CH-43's. I never saw a Warrant Officer with pilots wings, or for that matter flying a chopper. My recollection is the Marine Corps did not allow Warrant Officers to fly.
All crew chiefs were enlisted men and many could handle a chopper as I could. I learned how to fly stateside from reserve officers that needed a co-pilot to log their monthly air time. Being bored with needing to do this they taught the inquisitive how to fly.
They did have Warrant Officers flying observation planes in the Army, and they may have also flown choppers - not sure.
