fractional, good post..
TU, I agree that you would have a hard time explaining why I won't take the aircraft to LGW, but not the passengers. If you land safely in LHR, I cannot see why anyone would take off from the destination with the pax on board.
Also, there must have been ground staff at LHR, how else could they have turn around the aircraft? Did they have enough fuel for the additional flight? Didn't they require a loadsheet and a new flightplan? They must have had support.
Anyway, I don't have enough information about the real circumstances that night to make a correct judgement, I just find it very strange.
MR8