As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE TOILET CAUTION AFTER LANDING, JUST AS THE LEFT ENGINE WAS SHUT DOWN AND BLEEDS ON APU. WENT AWAY AFTER F/A WENT BACK AND LOOKED AROUND. PERFORMED EQUIVALENT SCENARIO AND OPS CHECKED LAV SMOKE DETECTOR. OPS CHECKED IAW AMM 26-16-01. COULD NOT DUPLICATE MESSAGE. OK FOR SERVICE. NO SMOKE IN LAV OR CABIN. OPS CHECKED GOOD.