There was several hundred witnesses to the missle strike as well as FAA video tapes. The early reports even carried som eof this information. There is a website about this event supported and controlled by professional airline pilots.
Thjere are several ongoing lawsuits attempting to get the FAA to release the FAA video recording of the rader images just prior to the crash.
There is even a thread here somewhere.
I'm sure there are a few dozen more every year. But coincidentally there are also hundreds of UFO abductee witnesses. The FAA radar tapes have always puzzled me, as FAA control radar simply isn't capable of detecting a missile. The RCS is much too small. Without the interrogator working, its almost impossible to see a small aircraft with that radar.
Alas, people often see what they want to see, and remember what they want to remember.