From the Report - "After departing Coolangatta the flight proceeded without recorded incident to Taree. At this point the pilot reported to Sydney Flight Service Centre that he was cruising at 8000 feet and estimating overhead Singleton at 1930 hours EST.
At the suggestion of Flight Service and with the agreement of the pilot, Flight Service and Sydney Air Traffic Control then began to co-ordinate a clearance to allow the aircraft to continue to track, more directly, via the coast and transit the Williamtown military areas; however this clearance was delayed because of uncertainty regarding the amount of cloud and general weather conditions to the south of Williamtown.
Some 8 minutes after passing Taree the pilot advised that he would continue on his planned track rather than hold to the north of Williamtown pending the issuing of a clearance.
He subsequently reported when passing the Craven position, and advised that the aircraft was experiencing "considerable turbulence now and quite a lot of downdraught". Five minutes later, at 1924 hours EST, the pilot reported that the aircraft had entered cloud. He requested a clearance to climb to 10,000 feet and shortly afterwards advised that the primary flight instruments, i.e. the artificial horizon and the gyroscopically controlled direction indicator had failed.
Search and Rescue procedures were initiated and at 1928 hours the aircraft was identified by radar. At this time the aircraft was near the Barrington Tops, some 58 km north of Singleton, and about 40 km Northwest of the planned track.
This information was relayed to the pilot , who advised that he was having difficulty in climbing to 8500 feet.
At 1934 hours he indicated that the aircraft was no longer in cloud, however it had accumulated "a fair amount of ice".
He continued to report strong turbulence and further ice accretion, and indicated that the aircraft was descending rapidly. The last recorded transmission from the aircraft was at 1939 hours, when the pilot advised the aircraft was at five thousand feet. Radar contact with the aircraft was also lost at this time." (my bold)
Bill, I don't see how you can say that MDX was "sent inland by the RAAF", when the pilot of MDX made his own decision to continue with his planned flight path, and elected not to wait for clearance over Williamtown.