Which of the following actions does the Commissioner's regulatory authority NOT allow in examinations and investigations?

The correct choice is one that indicates an action the Commissioner’s regulatory authority cannot take during examinations and investigations. The Commissioner's authority is generally extensive, allowing for a range of actions to ensure compliance and protect consumers.

The ability to subpoena and examine under oath any person deemed relevant is indeed a powerful tool in regulatory investigations, but this action usually requires prior legal processes or limitations defined by law. Therefore, it might not be within the typical authority exercised during routine examinations and investigations.

The other options represent actions that are typical and necessary for a robust examination process. Requesting documentation from financial institutions enables the regulator to review pertinent records to ensure compliance with laws and regulations. Conducting interviews with borrowers and lenders provides insights and testimonies that are essential for understanding practices in the industry. Inspecting property collateral for closed loans ensures that the collateral matches the documentation and is valid under lending practices, allowing for a comprehensive assessment during the examination.

Overall, the understanding of regulatory authority helps clarify that while the Commissioner can take many investigative actions, subpoenaing testimony under oath typically requires specific legal procedures that might not be covered under routine authority.