Professionalism in Reporting Violations

As an investment professional, John works for a registered investment advisor (RIA) and is tasked with handling client funds. During a routine client meeting, he realizes that one of his colleagues has been making personal investment decisions using sensitive information about upcoming transactions that hasn't been publicly disclosed. John understands the importance of maintaining ethical standards and confidentiality. However, he is uncertain about how to respond, considering the legal implications of his colleague’s actions.

According to the CFA Institute Code of Ethics and Standards of Professional Conduct, which of the following actions should John prioritize in addressing this situation?