Final answer:
A nurse who discovers a colleague stealing medicines must report the incident as outlined by the Nurse Practice Acts to ensure patient safety and uphold healthcare integrity.
Step-by-step explanation:
If an on-duty nurse discovers that a colleague is pilfering medicines, the Nurse Practice Acts generally require that the nurse report the incident to the appropriate authorities within the healthcare facility. The Acts often outline the duty of nurses to ensure patient safety and the proper administration of medicines. In the given clinical focus example, the repercussion of not reporting such an incident led to severe consequences, such as patients contracting HIV due to a healthcare worker who stole painkillers. This illustrates the importance of reporting to prevent harm to patients and maintain the integrity of the healthcare profession.