We had that, the rep agreed with the cops, who without talking to the motor bike rider, decided we had cut him up while he was over taking us. He was riding on completely the wrong side of the road, and as we found out later drunk and said he never saw our car. We got stuffed for the 'inspection' of the car damage by cops mechanic, 2k baht. Process went on for weeks, in the end no fine even though we were 'guilty'.