As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: RIGHT AT TOUCHDOWN MASTER CAUTION LAVATORY SMOKE WITH ALARM. FLIGHT CREW VERIFIED THERE NO FIRE IN FORWARD LAVATORY PER QRH. MAINTENANCE ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK OF THE SMOKE DETECTION SYSTEM PER AMM 26-14-00.