Larson Is the Owner of a Home in Eagle City,Iowa

Larson is the owner of a home in Eagle City,Iowa.He put the home on the market for sale.His good friend Bill,an attorney,came to look at the home for the purpose of possible purchase or rental.Bill noticed a crack in the ceiling and inquired about it to Larson.Larson informed Bill that there had been a water leakage problem in the area but it had been fixed two years ago and had not leaked since.Bill proceeded to make a written offer on the house which was accepted in writing by Larson the next day.On the day prior to closing the transaction,Bill went to the residence to make a final inspection.During the inspection,Bill observed water leaking through another crack in a ceiling of the house and in the garage.On the next day,Bill informed the real estate agent that he was rescinding the contract because of the leaks.Larson subsequently rented the property to another party.A couple of months later,Larson filed a suit seeking a court order to make Bill purchase the house or in the alternative for money damages.Bill defended by claiming that Larson either defrauded him or there was a mutual mistake and asked for the return of his earnest money and/or damages for fraud.The trial court found there was no evidence to find fraud on the part of Larson because the roof had been previously fixed and the two parties had been good friends.However,the trial court held that there was a mutual mistake of fact.What is the law with regard to mistakes? Was Bill under a duty to hire his own inspector to inspect the roof? What is the appropriate remedy when a court concludes that there has been a mutual or bilateral mistake of material fact?