Don't know about your state or area; but in my area the cops have video camera and the radar gun speed is displayed on the recording. This is evidence.
If there is no way for the Radar gun to imprint the read speed, then it comes into question. On the plus side, I have experienced several officers who have given me reduced tickets (87 went to 80mph) simply because I was polite and civil to the officer. Yeah, I was guilty, but having the policeman show a little mercy was appreciated.
So, I like the way things are done here; but in the article I have a lot of heartburn with the way things went down.
I do not know what they have here, but in the past it was the cops word against yours. Last ticket I got was my fault so that is not my real issue. Mine is like yours, his statement is not enough for me. To many instances of corruption withe the police now.