I don't recall all the details, but basically they could hear people pounding on the cockpit door, the hijackers pondering what to do about it, eventually the people breaking in, then lots of fighting and screaming. A key "fact" seems to be that the passengers poured scalding water on the hijackers. Anyway, my point was that this information source is about as reliable as they come -- and the authorities are not just guessing what happened through third-party phone calls.

Bruce