A rare exception
Not rare at all.
Most drivers are white. We should expect "most road rage perpetrators are white". But road rage is an equal opportunity offense. It is not due to some imaginary "White Privilege".
Most reported black offenders are in motorcycle gangs (off-road bikes) and harass drivers of all races. There are many such reports every year. Not rare.
But most road rage incidents happen very quickly and are never reported.