Planetruth,
I did not know about the 130 incident at Mildenhall in the 1960's, a few years before my time. I am sure that the British (or indeed any) government would be unlikely to admit that they had shot down an airliner.
Whatever happened to UA93 may never be known. The US government really were in a no win situation as they had one of two choices:-
1- Leave the aircraft and allow it to hit its target probably killing hundreds or thousands on the ground aswell as its passengers
or
2- Stop the aircraft reaching its target, which in practicality means shooting it down.
Personally I do not envy the person who had to make the decision.