Deseree prior to a discussion with Peter, offered $500,000 as opposed to $5 million in a contract to Peter. Peter accepted. Deseree said it was a mistake and asked to rescind the contract. What is the legal issue and for whom would the court rule?

Deseree prior to a discussion with Peter, offered $500,000 as opposed to $5 million in a contract to Peter. Peter accepted. Deseree said it was a mistake and asked to rescind the contract. What is the legal issue and for whom would the court rule?