Some years back, at PHX, the aircraft had tech problems three times. The ground staff stayed on for another four hours, getting pax on and off the a/c. It was the Saturday of a July 4 weekend: the ground staff were frantically checking on where to get rooms for a full 747-4 of pax, just in case. Eventually, we got off but the crew were in discretion: there were some moans from obviously junior CC, but everybody else really buckled down to get the a/c away and keep the pax as happy as could be. That was a really good job, and shows what BA staff can and will do - if allowed to.
I suspect that maybe the PHX ground staff - or a substantial number of them - are BA employees.