I guess my only thought about that is that he likely would not have got into the airforce, or got a pilot's license, if that was the case.
Apparently, name changes are lodged with the Births, Deaths, and Marriages register - so it is a permanent record. And you don't change your tax file number, just the name is changed on the tax file number.
Law enforcement, govt bodies (like CASA), and courts can access the name change record. But the public cannot.
So, if he had committed some heinous crime and then changed his name, when younger, that should have interfered with him gaining or retaining a pilots license.
(As per
Quora)
imo