I flew down a route similar a decade or so ago in a gutless cutless and found myself getting bounced around in pretty ordinary turbulence over rough terrain - I informed Willy of my level of discomfort and my desire to get down the coast in more desirable conditions and they could not have been more helpful.
Agree with the above comments ref "blaming" the RAAF - pretty long bow to draw! Perhaps if this gent had communicated his issues a bit earlier I am sure he would of received his desired clearance! Tragedy none the less and hopefully they can locate the wreckage one day.
Cheers