When an attorney is contracted to prepare disclosures and documents, isn't the lender still responsible for the accuracy of the disclosures? I don't remember where such a reference is stated, but I have always thought we are still legally responsible for the content and accuracy.

IMHO, you are right, the lender is responsible to the customer, courts, regulators, etc. The attorney is however responsible to its' client (the lender).

You can delegate authority, you cannot delegate responsibility.