It sounds as if the policeman wasn't happy that he didn't get the much anticipated OUIL/DWI charge he thought he had in hand so, in frustration, virtually made up a charge that consitutes a "your word against his word" argument since there's really no physical evidence. I might think that this whole charge might turn on the judge's mood that day and his/her opinion of said officer. It's worth a shot, though. Good luck!
DON'T BE TOO MUCH OF A HERO LINK