1. The "official" cause of the crash was utter bullsh!t, for a number of reasons -- including: a) the manner in which the FBI had to add an accelerant to stage the explosion in its simulation of the accident, and b) the lack of any scientific basis for their explanation that the aircraft actually climbed a thousand feet after it was torn apart.
2. IF the crash of TWA Flight 800 was an act of terrorism, it was destroyed by an on-board explosive and was not shot down by a surface-to-air missile.
3. IF TWA Flight 800 was shot down by a surface-to-air missile, it was an accidental shoot-down by naval vessel off the south shore of Long Island that night.
You should read his book or lwatch one of his newer videos (DVD) like "Mega Fix". He covers a lot of incidents with even more up-to-date info than what is referrenced in the book.