Unless they had a camera guy too... well theres no proof you were ever there. If you saw no flash and he didnt pull you over then hes prob not bothered.
Remember you said about 80. Your speedo is prob a liitle fast anyway and it might have been 75 or something in his gun.
They are looking for road warriors going 90 or 100 to bother chase as its a right faff to get back in position etc etc.
The guns don't have flashes, they have night vision.