Barber alleges that Nakatani galloped alongside him and shoved him off his mount after their horses crossed the line in a race at Del Mar on 3 August. He claims to have missed weeks of riding as a result. He is seeking damages for assault, battery and emotional distress.
Nakatani, best known in Britain for his victory on Cool Jazz in Ascot's Diadem Stakes in 1995, was suspended for the remainder of the Del Mar meeting by the stewards after investigation of the incident.
His licence was placed under probation for a year and was directed to seek counselling for "impulsive behaviour and anger management".