How do we fight a demonstrably false DUI charge?

My fiancé had a seizure while driving and rear ended the vehicle in front of him at a speed of less than 5 mph. The officer who responded falsely identified the post-seizure symptoms (drowsiness, confusion, amnesia) as intoxication and arrested him. When the officer got him to the station, the station nurse recognized his symptoms as something other than intoxication and he was brought to the hospital. A blood test came back negative on all intoxicants, but because the paperwork had already been processed, his charges went through. He previously hired a DUI defense attorney who attempted to get him to accept a plea bargain¿however, he does not want to accept punishment for a crime he did not commit, especially considering the long-term consequences. My fiancé has since been prescribed seizure medication, and has a signed letter from his neurologist that he has been seizure free for over six months. Wouldn't it be better in this instance to fight the charges, considering the evidence?