So to sumarise:
- unforecast fog at ADL
- diverted to MIA which had prob fog
- arrived MIA to actual fog
- no fuel to go anywhere else
Sounds legal (cue reference to 'worlds best practice' and QF fuel policy- but from these facts QF could have been in the same position). The mess was that they went to MIA.
Are there any other 737 airfields they could have gone to within the same range (Edinburgh but presumably it was fogged in also) that didn't have a fog forecast? Port Lincoln? Mount Gambier? (I have no idea if these can take 737s)
Did they know about the prob fog at MIA when they diverted - FlightAware shows pretty much an immediate 180 degree turn and dash for MIA - so either they didn't know or they did know and had no other choice but to hope that prob 30 didn't eventuate?