Investigation: 200401270 - Airbus A330-301, VH-QPC
Worth a look. Not as simple as being on final when the amended TTF was issued. Also have a look at the criteria the company and the A330 crew thought was required for an emergency airport to be used. The 744 crew did not declare an emergency to use CB. Same policy, different response.
My point is as much as the rules and regs try to cover all contingencies at the end of the day it is up to the crew to decide on the best course of action. I still consider that had a Cat III ILS been available in ADL then it would have been a more probable destination, especially for the QF crew as it appears that MIA is an emergency alternate.