Basically, Afternic offers to ensure that a buyers money is held until they receive a domain in their registrar's account. As learned in this thread, they cannot "insure" against dishonesty in the process either before the listing, or after the transfer, as is what happened here. In real estate, you have title insurance for that purpose. A comparable product apparently doesn't exist for "virtual real estate."
For a legitimate seller, they offer a supermarket style domain name classifieds, as well as a guarantee that if you follow their process, you will get paid from their certified escrow.
It seems that the Afternic process is still good for sellers, but as always, it's "Buyer Beware!"