The warranty agreement will help but may not provide total protection.
If there is an error on a disclosure the borrower can sue your bank, in addition to the original creditor.. The bank will then have to defend itself, which can involve many thousands of dollars of legal fees. What does does the warranty agreement cover? Does it cover only loan losses? Will it cover damages paid to the consumer? Does it cover your legal fees? Does it reimburse you for the hours spent defending the case?
Most banks conclude that they need to conduct due diligence.