As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HYD SERVO WHICH CONTROLS FORE/AFT CYCLIC MOVEMENT WOULD NOT SHUTOFF WHEN COLLECTIVE "HYD SHUTOFF" SWITCH IS ACTIVATED. THE SERVO CONTINUED TO OPERATE ON ACCUMULATOR PRESSURE FOR APPROX 20 SECONDS UNTIL ACCUMULATOR WAS DEPLETED. IN THE EVENT OF A FLIGHT CONTROL HARDOVER OR SEVOJAM, THE ACFT WOULD BECOME UNCONTROLLABLE.