Two police officers charged with dangerous driving and failing to stop at the scene of an accident were aware a crash had occurred, a court was told.
A third officer in the police car at the time said a crash occurred behind them on the opposite side of the road.
Insp James Wood told Aberdeen Sheriff Court the police car did not stop.
Pc Ashley Forbes and Ch Insp Tom Forrester deny dangerous driving and failing to stop at the scene of an accident.
Ch Insp Forrester also denies wilful neglect of duty.
Ch Insp Forrester was head of roads policing at the Grampian force when he was being driven to Aberdeen Airport by junior officer Pc Forbes.
Insp Wood said: "Constable Forbes looked in his mirror. He asked the chief inspector what he wanted him to do, and whether he wanted him to stop. I took it from that, there had been a collision."
Fiscal depute Mhari Morrison asked: "Was Constable Forbes aware something had happened?"
Insp Wood replied: "Yes."
Asked what was the response from the chief inspector, Insp Wood said: "The chief inspector was looking behind him and said something like, 'don't stop, it's only minor - you can come back and deal with it'. Constable Forbes was instructed to, and continued to drive."
The trial continues.