Consider a contract for the sale of a parcel of land from seller S to buyer B at a price of $15,000. After the sale is complete, the local government announces plans to build a highway near the property, which raises its value to $100,000. S sues to have the contract invalidated on the grounds of mistake. Suppose it is learned at trial that the land would only have been worth $5,000 if the highway had not been approved. What does this information tell you about S's claim that the mistake was mutual?