We just want to know what makes him an "aviation expert".
Slippery Pete, you must remember that it is the media that give him that title and it is in their interests to do so!
We probably all have different definitions for what "expert" means, but he easily meets my definition of "expert".
Get and read his book "Qantas Flightpaths". After you do, you will not begrudge him the title of "expert".