How about this scenario, BAA will not pay NATS for sufficient controllers to cover past 2300? NATS has apparently made multiple offers, but BAA not interested in paying for coverage. So hardly a NATS staffing problem, cannot understand why NATS are apologising for something that is not of their making.
Do not know all details of the AUR diversion, but understand that SOU closed on schedule at 2230 that evening and the aircraft had already re-filed to BOH.
Any coverage past 2300 is purely voluntary on the part of controllers. However have heard that NATS managment have in the past expressed their displeasure to controllers when some have not volunteered to stay for late arriving scheduled flights.
Don't blame ATC, BAA are the ones that should hold their hands up and publicly apologise.