Citizen's Complaint/Ticket

My wife was given a ticket after a citizen complained that my wife made an unsafe pass on a rural road here in Oregon. My wife claims that the pass was done safely, with turn indicators, and she did not cut off the lady being passed nor exceed the speed limit. There were no other passengers in the complainant's car. The passenger in my wife's car was asleep. It appears to be my wife's word against the complainant's. How is this able to proceed? The officer, when he delivered the ticket, told my wife she needs to plead guilty or no contest and pay the fine. Can we take the complainant to small claims court for filling a false report?

you can't sue for a false report unless you can prove it. the best way: you win your ticket case by the court dismissing the case on the merits.