Thank you for the opportunity to help you with your question!
Yes there are legal, moral and ethical issues. The legal issue arises in the sense that Garrett was an undercover investigator and was legally obliged to conceal his identity. Consequently, he cannot be sued for operating as an undercover. Additionally, the ethical issue arises in the sense that Garrett decided to uncover the criminal activity by being part of the team. He is obliged by the law to do so in what is described as the sting operation. He did not lure the other nurses into committing the offense hence if they are caught they will have a question to answer in the court of law. Moral issue arises in the sense that Garrett wanted to uncover the evil going on in the nursing homes. He is legally mandated to detect, investigate and arrest any law-breakers.
Please let me know if you need any clarification. I'm always happy to answer your questions.