A seller may say the watch was checked before listing. That can be useful, but the buyer should still know which serial was searched, by which service, and on what date. The person paying for the watch has a direct reason to confirm the result independently.
What a responsible seller can provide
A seller can share a legible serial, documents that identify the watch, an invoice, and the result of any prior search. They should explain the sale terms and allow a reasonable inspection. If privacy is a concern, the serial can be shared privately rather than in a public listing.
What the buyer should verify
Compare the serial on the physical watch with the one in the documents and the search result. Run your own check close to the transaction and retain the date. A previous screenshot may refer to another watch or a time before a report was added.
A dealer's process still needs a record
A dealer should record who supplied the watch, what identifier staff inspected, which checks were run, and when. Buyers can ask what the dealer's process covers. The check is not a substitute for authenticity inspection or proof of the seller's authority.
The best answer is not “the other side checked.” Both sides should be able to show which watch and which record the transaction refers to.
Verify the Watch Yourself
Keep the result beside the invoice and serial photo for the exact watch you buy.