DF flight was actually VA 1384
Hypothetical, on your way BN AD you fly past MIA, even though fog has been forecast all night, you look out the window, CAVOK. 15 minutes later get told AD has unforecast fog, and deteriorating below minima.
METAR MIA CAVOK at this time CAVOK.
What would you do?
As an aside QF also diverted there, did they have fuel for anywhere else