you assume a lot ...
You originally asked what else could she have done. According to all the information presented - she got a note on her windshield and filed a federal civil rights complaint - there is no mention of any threats, any contact, nothing.
So, she COULD have done the things I mentioned first ...
As to HIS actions - definately not in order.
All that is necessary for the triumph of evil is that good men do nothing
From personal experience, I can say with relative certainty what would happen is fairly predictable.
1. She calls the Supervisor and files a complaint
2. Supervisor makes fun of the officer, everyone laughs at the officer and makes fun of him.
3. She is now targetted by every cop on the force, to put her 'back in her place'. She will suddenly and 'mysteriously' have more traffic stops, speeding tickets, brake lights out, etc.
4. Cop who used this practice, resumes the practice until the cycle repeats.
And, honestly - I think we will both acknowlege that there are cops that can intimadate single women into getting 'whatever' they want, however 'frequently' they want it; before moving on to the next 'target'.
This insures that the cycle is broken, and sends a clear warning that people in this perpetual cycle have been duly warned.