Voidable Contract

Sam Student had borrowed $1,000 from his cousin. Sam and the cousin became involved in a heated disagreement when the cousin began to press Sam for repayment of the loan. Finally, Sam wrote a check for $190 to the cousin and conspicuously wrote on the check in big letters that it was full and final payment for the $1,000 loan. In need of money, the cousin cashed the check and demanded the other $800 from Sam. Sam refused to pay, that they had entered into an accord and satisfaction that discharged Sam's obligation to pay anything more. The cousin sued Sam. Discuss the probable outcome.