I do not wish to comment directly about this incident as I know nothing about it, I wasn't there and I have no experience of VS.
But, There just may be a wider issue here. In my airline, crews are getting worked so hard (legal but unsympathetic rostering with most crews disgruntled and borderline fatigue) that there have been a couple of minor instances of crew members spitting the dummy when ordinarily they would not have done.
I am not suggesting that this may have been the case here but I would be interested to hear the views of any within VS and other airlines.
Possibly another case of airlines being "run" by accountants ("We can save the cost of a standby crew and we will just put the inbound crew on min rest if anything goes wrong, and anyway the cost of hotac for a 747 full of pax will be more than saved by not having a standby crew in MIA. To hell with pax loyalty and crew morale and health because its an employers job market") and then blaming the professional operators when the wheels come off.
Comments?