Both aircraft safely arrived is what matters, whether each followed the rules is debatable. It's interesting that the QF aircrafts fuel details were not obtained by the ATSB for that event, and they had to use a calculation for the estimated FOB. In the Mildura case this was definitely a case of CAR 257 where decent below minima is allowed due to no other course of action available, ie an emergency. In the case of the 330 mentioned earlier its interesting, they had to declare an emergency to use Canberra as an alternate, but then busted minima at Sydney, which was also allowable under CAR 257 due to a fuel emergency, but is there a fuel emergency when you have fuel for an alternate? What is safer, busting the minima or diverting to an 'emergency' alternate under company policy, which would be considered a suitable alternate for general operations. It's pretty obvious from some wording in that report that the ATSB seems to think that the pan call was given to 'push in front' of other traffic so they could have a go before getting to YSCB divert fuel, but they only remarked at it, not really pushing the idea. It really is unfortunate that the briefing QF gave the ATSB/ATC on the why things are that way is not explained to the pilots in general for our education, as it would be nice to know the answers to these questions of what is preferable. This latest Perth Mayday was not really similar to either event as both the previous were due to weather conditions, not prolonged traffic holding.