Re: Another 'impossibility' . . . ?
The plane exploded. That implies stuff was hurled from the plane, inside and out. Some of this debris could have survived to street level, and likely did, as evidenced by the existence of the passport.
As for the Pentagon being unable to protect itself, this has changed. Prior to Sept 11, 2001, when was the Pentagon ever placed in jeopardy? ...And military service members as game-show contestants don't count.
Whip it some more, sp. That horse may yet twitch.
Dan