As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AIRCRAFT WAS NOT GROUNDED. AFT RIGHT HAND LAV MOMENTARILY ILLUMINATED SMOKE/MASTER CAUTION AND SIX PACKS OVERHEAD. THE WARNING WAS 3 SECONDS, WITH NO FUMES OR ODORS. ACCOMPLISHED VISUAL INSPECTION OF LAV AND OPS CHECKED SMOKE DETECTOR. NO ANOMALIES NOTED. DETECTOR OPS CHECKS GOOD. REF AMM 26-14-00.