I believe their should be more freedom for people to post about suspicious activity within a sales thread. Generally when the public as a whole can collectively evaluate or even compare with similar experiences, it is more likely to lead to more legit sales taking place on this forum. If you have nothing wrong with your domains and traffic stats are accurate, and you are willing to stand behind it, why should you care if potential buyers can ask questions or inquire about something publicly.
At the very least, there should be some kind of "Alert a Mod" option with a place to describe a potential descrepency if someone believes there is one with a particular sale. A "contest" button if you will.
At the very most, open discussion when there is solid proof of a mis-translation, or artifically inflated stats, etc... should be allowed. It hurts the sellers, but only the ones trying to misrepresent a sale. If people are wrong about a seller, it adds that much more credability to the seller's future sales because they've been examined already by the public.
Most of the cases in which false sales are identified are by users who post about it, and are usually right.. it seems if they're wrong they get warning points, and in most cases it is just so obvious they feel they have to let everyone else know, so that no one is potentially duped.
