Efrem Zimbalist Sr. contracts to buy 2 violins from a violin dealer. One is thought by both parties to be a genuine Stradivarious and the other to be an antique Guarnerious. Following payment of the $20,000 down payment, it is discovered that neither are genuine. Efrem fails to pay the remainder of the purchase price and the Seller sues for breach of K. Efrem contends that the mutual mistake as to the identity of the subject matter rendered the K voidable. Is he right