A contract will not be reformed due to mutual mistake if the party seeking reformation was not reasonably diligent in discovering the mistake. Parol evidence is admissible to prove a mistake in a deed or any other contract required by law to be in writing.
In the first case, the son stated that the trial court erred in holding that he waited too long before seeking a change to the option contract. The Court of Appeals agreed that the son exercised his option within the 10-year period, and was, therefore, timely. The true terms of the contract were not set forth in the option contract due to an mistake by the secretary.
Was the son's reformation untimely and was there a mutual mistake in the option contract?
No and Yes
The court held that the ruling that the denial of the reformation was reversed, and that there was a mutual mistake in the formation of the contract.