Metro Man, I know, it was just an example to illustrate the point that it's of no operational relevance whether the probability is 10 or 90%, it still requires the carriage of an alternate or holding. So why not just ditch the number or the term PROB entirely and just forecast it - the operational impact is precisely the same. PROB30 might give you a warm fluffy feeling that it's 70% not likely to happen but is operationally of no relevance.
It states in the jepps somewhere (will try and get the reference) that for nomination of a suitable alternate that prob30 is except able without requirement but prob40 too will need an alternate.
That said, I believe tha the VA crew had nominated ML as there alternate so very curious as to why/how they ended up in mildura.
Can someone in the know advice if Qantas have an RNP approach into mildura? That might explain how they got in with presumably no dramas whereas virgin did what they did.