What are the principal objectives of the SEC rule that requires Form 8-K statements to be filed

Question:

What are the principal objectives of the SEC rule that requires Form 8-K statements to be filed when public companies change auditors? Did Shepherd violate the client confidentiality rule when she discussed the United Airlines–Cardillo transaction in the exhibit letter she filed with Cardillo’s 8-K auditor change statement? In your opinion, did Shepherd have a responsibility to disclose to Cardillo executives the information she intended to include in the exhibit letter?