Knowing how VNA "operates" I would think that this story needs a little more than just face value acceptance of a fake pilot? As someone mentioned in a post above, the viet "captains" (loosely termed) will not accept responsibility for their own actions and are on the look out to "blame" anyone and everyone for their lack of competence/qualification etc. when the weather is bad or if things look like they might be "difficult" these Heros call in sick every time.
If anyone is holding a "fake" or dubious licence, I would be looking first at the Vietnamese card carrying communists and all round back slapping mates club?