As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: AFT LAVATORY AND SMOKE DETECTOR MASTER WARN INDICATION SPURIOUS SIGNAL LASTED 30 SECONDS. FLIGHT ATTENDANTS CONFIRMED NO SMOKE. ACCOMPLISHED AFT LAVATORY & SMOKE DETECTOR POWER UP TEST AND RESET AS PER AMM 26-17-00.