I think I can agree with both sides of this story in part, but both sides inflamed an already difficult situation.
It seems that the passengers had been looked after as well as possible by VS. I cannot understand why a £3500 Business class ticket hadn't entitled Mr Warshaw to a reroute the day before, perhaps it was non transferrable and not full fare?
So having been put into a hotel and been well looked after the passengers decide to be sarcastic and boorish when the crew turn up. They didn't wait for any explanation before launching into this response.
In my experience, and that's 27 years in pax and ground handling, most passengers would be glad to see the crew arriving as that signalled the imminent start of their journey home. If the crew were met by 'mocking applause' then they would have been stoked up by a ring leader. It is also likely that this ring leader had been stirring the day before and at the hotel. Sometimes it is justified, more often it is someone trying to act big in front of the other passengers. Invariably their behaviour is offensive and their claims of injustice exaggerated.
I agree that an announcement by the ground crew explaining why the crew were late to the airport (assuming they were?) would have helped, as would an announcement after they had arrived.
If we accept that the passengers had a right to be sarcastic and mocking to the crew because they were late, then I cannot wait to employ the same rudeness on the many passengers who delay flights by arriving at the boarding gate late!! It cuts both ways don't forget.
To ban the passenger on the basis of what has been reported does seem a tad harsh, but my gut feeling is that there was more to the story than has been told so far. No airline invites bad publicity willingly and banning someone almost always leads to bad publicity.