As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT. 8695 SEA - BLI AIR TURNBACK/ DISCREPANCY: AIR TURNBACK DUE TO UNCOMMANDED AUTOPILOT ENGAGEMENT AND THE STALL WARNING STAYED ON DURING CLIMB OUT. NO EMERGENCY DECLARED. LANDED WITHOUT FURTHER INCIDENT. CORRECTIVE ACTION: MAINTENANCE RESEATED THE AUTOPILOT COMPUTER AND CLEANED THE STALL WARNING. ALL CHECKS GOOD. NO DEFECTS NOTED.