Neither crew were aware of this TAF nor would they have been able to use this forecast in support of their decision to divert..."
BUZZBOX I agree that my last post was in very black & white terms but the operative phrase is in your quote (above).
From memory, there was also a missed approach at YMIA that was not passed onto the crew. I also have a recollection that buried somewhere in the report is something to the effect that the BOM forecast the fog on the basis of satellite imagery rather than ground observation and that there was a ground observation that conflicted with one of the revised TAF's at the time of its issue.
My question would be, would we be better off if the BOM rang people for observations rather than looking at satellite photos & computer models.
But, the information that BOTH crews had available at the time of the decision to divert was that Mildura has vis > 10km with broken cloud in the mid 3,000ft range.
There was information that was on hand that conflicted with this, but it was not passed on to the crew by any of the BOM TAF's or METARS, or via ATC or via the company dispatchers for either airline.
If I was given a METAR that agreed with the TAF for an airport about 35 min flying away that easily allowed a VFR landing, I reckon I'd assume that I could rely to be an adequate IFR diversion.
Someone commented earlier that the big issue that we were all missing was that the ATSB was again attempting to deflect criticism for other government agencies.
The ATSB in the past has presented a timeline as part of the report. The drafting of this one makes it difficult to put all the pieces in correct order. I think it might be clearer if they has presented a chronological list of events.