Just speculating about the pilot ... It's known that he's the kind of guy who isn't satisfied with shagging the air & ground crew but has, at least once, chosen to hand-pick pretty girls out of the boarding queue for flirty company on the flight deck, against regulations. Aviation tends to attract risk-seekers. Despite regular psych checkups, quite a few pilots are narcissists (who can have spectacular disturbances from time to time) and fewer have untreated bi-polar on long cycles, with the manic part of their disorder provoking the risk-seeking. There's a high incidence of alcoholism and other drug abuse. Don't ask me how I know about this, it's a long story!
The pilot in question could have had a god-like episode, where he decided to do something utterly irrational that seemed sane & feasible to him. Or he could have been flattered & manipulated into taking part in an astonishing crime, believing it would grant him riches & glory. I know there are checks and balances in place, which empower crew members to contain a colleague who's gone off the rails. But I don't know how well they work in practice if needed.
I kind of assumed the Australian blonde told her story to illustrate the pilot's a bit of a loose cannon. If the plane's "never found", though, he will make an obvious fall-guy whatever really happened. So - er, this speculation's a bit pointless, really 