BA is a private airline and has no more obligation to provide medical services to the public than any other airline operating into LHR. Airclues post said it all- the ambulance is only dispatched at the request of the London Ambulance Service controllers, trained personnel who are more qualified to decide on the best course of action than a couple of BAA security guards. If LAS decide that one of their vehicles is better placed then who are any of us to argue? Case closed. Unless of course you think the LAS and BA are in cahoots now.