As far as I know, the FBI never made a determination about TWA 800. But 9 knots of wind is more than enough to blow a burning piece of check stub 8 miles. And without seeing video or a series of photographs of smoke from a fireball, there isn't any way of determining which way the wind is blowing (or how hard). I don't believe a video of the fireball from Flight 93 exists. What does exist is weather observations from the region on 11 September 2001. They say the wind was blowing in a southeasterly direction at 9 knots. Unless you believe the NTSB changed all the weather reports, I'd say it is pretty safe to assume the wind was blowing at about 9 knots that day.
By Wednesday morning, crash debris began washing ashore at the marina. Fleegle said there was something that looked like a rib bone amid pieces of seats, small chunks of melted plastic and checks
Explain how the wind blew this stuff into the lake. Also, you do not need to see a video of the smoke from the crash. The still photo shows the smoke going straight up. If there was a breeze the direction of the smoke would not be going straight up.
The FBI backed the finding of the Flight 800 investigation saying it was a fuel tank problem. They discounted all the eyewitness reports and did not even investigate them.