Apparently the 'conversation' that sparked suspicion went along the lines of:
"We've been planing this for 6 months, you can't back out now".
Origionally construed by a passanger as a terrorist conversation, the captain bolted the door and quite correctly took the necessary steps. Speculation on the ground then moved to the possability that the pax were discussing a buisiness deal, but I believe the true nature of the conversation turned out to be a contraversial family reunion. Speculation aside, the machine swung into action and a well prepared plan was executed like clockwork by all concerned. The actual alarm was raised slightly earlier than the BCC state, nearer 0810 BST. RAF Fighters were alerted & launched within timescales stipulated by Parliment. A great deal was made of the distance maintained by the fighters, but the media / public should not under estimate the range & accuracy of the latest 'Fire & Forget' munitions carried by the UK air defence force.
As a mere, well informed, spectator to the action, from my perspective, the crew, air traffic controllers, air defence controllers, air defence crews, and ground side security forces involved all did a fantastic job and have convinced me of their undoubted ability to deal with a more real incident should the need arise, heaven forbid. (And I never thought I would hear myself praising the Scopies!)
Hippy.