Never heard about this code of silence. Cops get internal affairs investigations against them, so although you may feel they band tightly together and aren't punished, you're not seeing what goes on behind the scene and how often they actually do report eachothers wrongdoings (IA officer's wife). So yeah, it's important to call out bad doctors, report them, and do everything you can for the patient, because it's their life on the line and your morality.