At that time we regularly saw unlit aircraft in the moonlight heading south over the Timor Sea and into Central Australia from out 35,000 lookout. Its a big country and I'm sure lots happens out there even now.
Who remembers the incident back in the 70's of the virtually brand new Shrike Commander that was intercepted by a RAAF Hercules (I think) and eventually forced to land on a bush strip, but was subsequently torched by the Pilot because it was 'loaded to the gunn'ls' with giggleweed!
A bloody waste of a good Aircraft!