For example, the deal is that BrokerSneaky mails a payment to Seller. Seller has placed something in escrow as required by BrokerSneaky. BrokerSneaky DOES NOT mail anything, but instead gets HaplessBuyer to mail the payment by giving HaplessBuyer some reason to send the same amount of money that Seller charged BrokerSneaky. Seller receives the payment from HaplessBuyer and instructs escrow to release its holdings to BrokerSneaky. BrokerSneaky disappears without giving anything to HaplessBuyer (who wasn't smart enough to demand an escrow).
What legal claims, if any, does HaplessBuyer have against Seller?