Every time the police stop a vehicle, it is a DUI investigation. It is the way they are trained. If they smell alcohol you will be asked to get out of the car. During the investigation, the police are trained to write down items that are consistent with DUI. They won’t provide all the facts that indicate a potential innocent reason for their observations.
An officer is trained pursuant to the National Highway Traffic and Safety Administration (NHTSA) that a person 65 years or older has difficulty performing Field Sobriety Tests (FSTs). However, you will not see in a police report an officer noting that poor performance could be as a result of old age.
There are many other medical conditions that could be interpreted by a police officer as intoxication. A person performing FSTs when he has had knee injury or surgery, hip problems, back problems, head injury and so on.
So, when you have been arrested for DUI and review your police report written by an “objective” police officer, don’t be surprised. They are just trained that way.