Quite a while ago, there was a very plausible story on a DC radio talk station, which said that if terrorists shot down Flight 800, then the Secret Service (& FAA) could not guarantee the safety of air traffic in the US. Consequently, the President would have to travel by train. Ergo, Flight 800 was not shot down by terrorists - no matter what eye witness saw or what available films showed..
This was a case when the nation was under attack, and we were too "dumb" to realize it. Lets see, whe was President then? Did his name begin with C?