Good for you Dan. Believe what you like.
I saw it, I figured it was a contrail, albeit unusual. There are clinchers. First that it moved in the lower eastern part of sky over a period of several minutes at a speed impossible for space junk or a meteor. and too fast to be the remnant cloud of similar (both of which I have seen at other times).
Secondly, flightradar 24 shows an Emirates A380 in a position east of Hobart at approx 201702271940Z.
It was dawn so it was being lit up underneath from our ground perspective.
But as I said I respect your right to believe what you will. It doesn't make you right though.