he would have to of given you a verbal NIP right there.. if not then you cant be taken to court..
They can however prosecute you if you were speeding as in their 'expert opinion' you were going to fast.. speeding is an absoloute crime so it doesnt matter if you were doing 41 or 101 (except for points/fine) you would still be guilty of speeding and recieve 3 points and the standard fine.