In late 2007 or early 2008, the plaintiff, Lan England, agreed to sell 258,363 shares of stock to the defendant, Eugene Horbach, for $2.75 per share, resulting in a total price of $710,498.25. Although the purchase money was to be paid in the first quarter of 2008, the defendant made periodic payments on the stock at least through September 2008. The parties met in May of 2009 to finalize the transaction. At this time, the plaintiff believed that the defendant owed at least $25,000 of the original purchase price. The defendant did not dispute that amount. The parties then reached a second agreement whereby the defendant agreed to pay to the plaintiff an additional $25,000 and to hold in trust 2 percent of the stock for the plaintiff. In return, the plaintiff agreed to transfer the stock and to forego his right to sue the defendant for breach of the original agreement. In December 2010, the plaintiff made a demand for the 2 percent stock, but the defendant refused, contending that the 2 percent agreement was meant only to secure his payment of the additional $25,000. The plaintiff sued for breach of the 2 percent agreement. Prior to trial, the defendant discovered additional business records documenting that he had, before entering into the second agreement, actually overpaid the plaintiff for the purchase of the stock. The defendant asserts the plaintiff could not enforce the second agreement as an accord and satisfaction because (1) it was not supported by consideration, and (2) it was based upon a mutual mistake that the defendant owed additional money on the original agreement. Is the defendant correct in his assertions? Explain.