Agree Richard, buyers should only trade with whom they feel comfortable and trust.
Clearly on Rolex its not just about inexperienced buyers though as there is often doubt as to authenticity of dials/bezels etc, which would/could catch out all but the best trained eyes.
That would be why i would only buy from the best sources and those whose return policies i felt comfortable with. As a buyer if you take a punt, you may live to regret it, and with vintage watches authenticity is everything.
Nobody is forced to buy, some responsibility lies with the buyer, to do due diligence.