Why would you declare a mercy flight and plan to YSNF when you have NWWW 400nm away, and in the scheme of things bugger all out of the way for a flight to Melbourne. why not just plan via there where you have alternates close by in the first place?
If pelair stopped going there due to failing ramp checks as someone has said in an earlier post, maybe they should have fixed the things they were getting pinged on instead of not using NWWW (if it is true that is) and if it was fuel policies they were getting in trouble for then maybe NWWW had the right idea getting up them!
I know nothing about them not using NWWW for this purpose other than what I have read in here, and just for info.
It will be interesting to see what comes out of the CVR if they find them and recover them.
Swiss cheese effect at play here.