As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNCOMMANDED ROLL/YAW AT 31000 FT, 77 MACH AUTOPILOT ENGAGED, A/C ROLLED HARD LEFT. REQUIRED 40-50 DEGREE AILERON TO TO RIGHT TO COUNTER COMMAND ROLL. POM COMPLIED WITH YAW DAMPER DISENGAGED. A/C RETURNED TO NORMAL FLIGHT. REPLACED YAW DAMPER COUPLER AND RUDDER PCU PER M/M. REMOVED AND REPLACED FLIGHT DATA RECORDER FOR INVESTIGATION.