A "major reduction in speed" can occur when a LOT of things happen. Elmer Barr, for example, has a pretty plausible explanation that the front cabin door was defective and blew off; and he has a pretty good development of exactly how this would result in precisely the pattern TWA 800 showed.
My point remains: there is pretty conclusive evidence out there that would solve this, and the effort ought to be in getting that. My suspicion---and I'm not "calling names"---is that NOT having the radar evidence is convenient to the conspiracy crowd. But like I say, I'm certainly willing to believe it if the tapes show it.
BTW, I noted in the article that EVERYONE admits one of the "unidentified" signatures was a Navy P3, which is not part of the equation---except its radar was malfunctioning.
So all that remains is ONE unidentified signature that the FBI refused to comment on. Note that we are not talking about a signature that shows up repeatedly on a path heading to TWA 800 (as far as we are told in the article) but is a "one-time" sighting.
MY point is that missiles will give off fairly constant signatures, and as many radars as were operating that day, well, we'd have a boatload of evidence on a missile.