This wouldn't prevent scammers from scamming. SR has always, always, always warned about the dangers of finalizing early. The escrow system is in place to offer protection to vendors and buyers -- when someone finalizes early and chooses to leave the escrow system, they are in effect choosing to forgo that protection. Stay in escrow, do not finalize early, and you won't be scammed like this! Or, if you are somehow scammed, at least by staying within escrow you can go to the resolution center and receive a refund.