Bog, let's say things had been slightly different. When the pilot asked at the briefing office if he could flight plan over Willy he was told. " yes. Go ahead. That's clearly the safest route for a night VMC flight in these weather conditions"
As he tracked over Taree he was told to call Willy approach as they had a flight strip and new he was coming .A clearance was issued without requiring holding OCTA.
The aircraft remained in VMC. Out of cloud and icing and arrived safely at Bankstown.
One can just as easily speculate that with vac pump failure, leaning AH, wandering DI, dickie ADF, electrical issues etc .........., the PIC would have rolled it over and lost it anyway!