Simply by seeing emergency vehicles surrounding his aircraft is reason to evacuate!
What if the reason was some loony running around shooting people was hiding under his aircraft.
He should do as he is told and hold, if he is not happy with that
discuss it - not just not follow instructions.
I find his demand to have info given over the radio very foolish - that could be heard by a person with the detonator and then they may have pulled the trigger.
We don't know the background of this bomb threat (well I don't) but if I were asked to call that number and clearly knowing something was up, I would have clicked this is private sensitive info that they can not say over radio.
BOMBS PART 1. THREATS! WHAT TO DO? - Aviation Above