Which situation doesn't require the CDC to report to J3 CD NGB?

The situation involving a minor traffic accident with a General Services Administration (GSA) vehicle does not necessitate reporting to the J3 CD NGB (Joint Task Force Combat Development National Guard Bureau). This scenario typically falls within the realm of regular operational protocol and does not have implications of a security breach or significant risk that would warrant immediate higher-level reporting.

In contrast, the other scenarios relate to more serious situations that could have broader implications. For instance, the loss of a government weapon poses a potential security risk and could affect national defense, thus requiring urgent communication to the relevant authority. Exigent circumstances involving escalation suggest a situation that could quickly develop into a critical incident, necessitating immediate attention. Injury during training exercises may also require reporting, particularly if the injury might impact operational capability or involves significant medical concerns.

Therefore, the correct answer highlights a situation that is less critical and better handled within standard operational channels rather than through emergency reporting protocols.