The charge is not 50 in 40 or 50 in 45. It was that you were going faster than the posted, safe, or maximum speed (depending on just what he cited you for). Even if there is an error, he doesn't need to write a new ticket. You'll be found guilty by your own incriminating statement. Even if you were written up for the posted speed violation, there's no difference in Kansas for 5 or 10 over.