CPA firm's errors in preparing irrevocable trust tax return, remedies in CA

CPA accounting firm errors on tax return: A CPA firm prepared my irrevocable trust tax return along with numerous other family members (they have the same trust, same money manager) for the last 10 years. Last year I decided to prepare the return myself because the cost to prepare the return had ballooned. After reviewing the past years returns I discovered the accountant had not expensed the preparer fees AND the money mangers fees, which total over 20k. The strange thing is the other 3 trust returns had the fees expensed. Since the statute of limitations has passed, I cannot amend the returns. Do I have any recourse against the CPA firm? - Is this your question? Add additional information