Ok, I'll try to put this 'properly'.
I don't see any issues with those people in 'positions of power and responsibility' reacting strongly to this.
They were in their offices, minding their own damned business when they were told (more or less) 'run for your lives, there's an airplane about to attack us!!'
From a supposedly responsible security force, that's not a warning that's going to be taken lightly.
To later find out that it was:
A - Not a threat at all.
B - A plane operated by the US Military.
C- That the people investigating it are starting to falsely lay blame (story says that "Officials believe, based on a preliminary review, the pilot may have not properly reported taking off or had appropriate clearance", yet also says "Air traffic control recordings capture the army plane coordinating its flight with the control tower at nearby Ronald Reagan Washington National Airport.").
Would be rather infuriating.
To insist that those responsible for it be held accountable is not unreasonable.
I have no clue who screwed up.
I doubt it was the GK. They've done this too many times in too many places not to know the drill. And, being 'the Army', I'd bet very heavily that they have a written procedure that details all the steps, including those that cover notification of proper authorities.
Did the FAA fail to notify the security people? Perhaps. I don't know the procedures and such for authorized flights into that sort of restricted airspace. For the plane to be in contact with ATC AND in that restricted area means someone at the FAA knew about it and was ok with it. That doesn't necessarily mean that the FAA passed the info onto the security folks, but I think it makes it less likely that the screwup was at the FAA.
My first instinct is to blame the security guys. They are the ones who never bothered calling the FAA (control tower) to see what was up.
They are the ones who over-reacted and ordered the evacuation.
Did the message get sent and never read?
Did the person who received & read it not pass it up the chain of command?
Did it get 'lost in the shuffle'?
I don't know.
I'm rather curious to find out.