The fact of the matter is that as from the moment you announce a bomb threat or a hijack to the authorities then you are no longer really the captain of your aircraft.
You will be told where to go and you will be told where to park on the remote stand at an airfield that you had not really planned.
Whatever you might wish to do as a captain on arrival will have been largely overtaken by the threat assesment team. I think you will find in law that they have now taken over the responsibility for your aircraft and its contents.
You could always decide to disregard their advice and launch yourself out of the DV panel and probably break your leg on the ramp.
Whatever your grandiose ideas of being the perfect captain might be, you will have to listen to the advice being given from outside.
I reiterate that if you choose to disregard this advice and go for your gung- ho attitude and evacuate the aircraft, you could subsequently find yourself in DEEP sh*t. For all you know, the SAS could (and probably will be) outside the aircraft and you could end up with an AK47 round up your arse.
I am not impressed by the statement that folks can step out of a 737 without any problem. An ex-mate found himself in deep sh+t when he fell out of Door L1 from an easyJet 737 at EDI.