You would think. Would the pilot being tailgated question it and call it in?
Last I heard its possible to stay a thousand feet back and actually several thousand feet lower and any radr in that area would see just one, would not work in CONUS and heavily populated or military areas. It would work there.
I tell yo what I had a pair of F15’s just taking off in Anchorage (F somethings)as I was flying a Cessna 150 over Point McKenzie, I was in the wrong place and corridor and I never heard them until they went by me.
If a pilot did think something was there what to do? A big circle?
I don’t think that would help. If they were that close, someone would notice."
Think about it.
Do you really think that the pilots, passengers or cabin crew can see directly below or behind the aircraft?
When I fly I like look out the windows to try to recognize landmarks. I will often walk to the back galley to look out the windows on the exit doors also. There is usually a blind cone about 45 degrees wide behind the aircraft and perhaps 30 degrees wide below.
Airliners are not fighter aircraft where the pilot needs to continually "check his 6 for bogies."
When the Air Force intercepts and follows a target they get 1000 feet below and a short distance behind the other plane. They cannot be seen there.