Actually some years ago I was at a military air show in Europe and something very similar happened. I was at the edge of the airfield with my two sons so I could see the jets fly by us very close at subsonic speeds, and was able to see some strange thing sitting up in the sky observing all the aircraft. Military forces from all over the world were there (Deblin, Poland) including the USA and Russia. I told my wife about it and she thought I was hallucinating, later, in the local press and the German science monthly "Focus" appeared some photos that a Polish colonel had taken of some French "Alpha" jets... in the picture was a clear picture of a UFO exactly like some photographed at other locations around the world.
During the air show, nobody saw a thing.
Years later, I took a bunch of pics at an air show and had some strange things show up. I decided that since I had a digital camera, I would just shoot a thousand pictures and did... in one of them was a strange object that I did not observe while watching the show.
Wow!...that makes it even stranger.