I recall from the reporting in the very early days, when mention was made of a highway cam, the the plane had to have crossed it's view point or vantage point.  No plane.
  I noticed today, when looking up some things, that the early interviews with people who were there are either gone or I just didn't dig deep enough.  But to me...these raw interviews are the most accurate and the most reliable...as they are gut reactions....no outside influences.  Several....and I remember it clearly, said the same thing in spite of not being interviewed in a group.  As you mentioned, van guy....the smell of cordite and "it sounded like a missile".(not a hundred percent on the cordite....and I'm not even sure I knew what that meant....it just came out as I was writing this....so I'll stick with that...lol)   Although I have no idea what a missile sounds like....I DO know what a plane sounds like....as I'm sure these people would as well.