Who said he's a security expert? That's a title Craig has given himself, but given he gets hacked regularly when it's convenient for him as an excuse I'd say I'm more of a security expert than Craig.
I don't think that australian stock exchange would hire someone incompetent for monitoring their systems .
That is utter nonsense. Companies hire incompetent and lazy people all the time. Have you ever heard of terms like nepotism or bribery? Craig is exactly the type of person who would lie, cheat or try to buy his way in. Obvious example: plagiarizing his PhD thesis or lying in court about his expertise, while physical evidence says otherwise.