The phrase "blew the whistle on" means to report or expose someone's wrongdoing to authorities or the public. Antonyms for this phrase could include ignoring misconduct, covering it up, or being complicit in it. Other words that convey the opposite of whistleblowing may include collusion, concealment, shielding, or protecting. However, it is important to note that using these antonyms in a positive light goes against the principles of transparency and accountability. Whistleblowing is often necessary for the greater good and may even prevent serious harm or danger. It is crucial for individuals and organizations to prioritize ethics and integrity over personal gain or loyalty.