As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ESTABLISHING CRUISE FLIGHT ON THE WAY TO A SCENE LOCATION AND NOT UTILIZING REMAINING POWER AVAILABLE PILOT PULLED MORE COLLECTIVE TO EXPEDITE EN-ROUTE TIME. ONCE REACHING APPROXIMATELY 85% TRQ, TRQ DROPPED WITHOUT PILOT MANIPULATION, OVERCORRECTED AND THEN SETTLED, CAUSING THE AIRCRAFT TO YAW. HMU WAS TROUBLE SHOT AND FOUND TO BE FAULTY.