Although I happen to know a Navy Air Traffic Controller who says there is irrefutable evidence that flight 93 was shot down by two F-18's over Penn.
That is officially CT talk.
It goes against the official story.
Your friend is a conspiracy theorist by definition. He believes something other than the 'official version'.
True, the debris was spread over 8 miles and the witnesses said fighters brought it down.
True, some canadian military guy admitted it was shot down.
True, Rumsfeld admitted we shot it down (on video).
True, the NBC chopper on the scene BEFORE the police arrived showed an empty hole with no fire or debris.
But... if it's true we shot it down, then our govt killed citizens (to prevent bigger injury, yes), but did it and lied about it. That's big. Hard to take their word on the other events of the day - especially when the pentagon crash had equally small amount of plane debris - when they so obviously lie about this one.