Before I was a lawyer, when I was a public information officer for the state office of a federal agency, I had a fantastically corrupt boss. We're talking blatant theft, falsification of travel, and other genuinely bad stuff. To save the job of an older co-worker who was also a good friend of mine (it's a long story, but basically the boss was trying to blame his theft on the co-worker), I reported this fine fellow to (1) the State Director of the agency; (2) the investigative arm of the Department of the Interior; and (3) the FBI. They all thanked me profusely for my courage, yada yada yada. The bottom line: the only people who suffered any adverse consequences were those who cooperated in the investigation. The corrupt boss stayed in his position another 20 years - with NO CONSEQUENCES WHATSOEVER, apart from some temporary embarrassment. At the very beginning, he snarled at me "Lots of other people have tried to get me. No one ever has, and you're not going to get me either." And he was right!
I have the satisfaction of knowing that I did what was right and helped my innocent co-worker, who was able to move on to a different job. I also came to believe this boss had been sent into my life by God as an absolutely perfect example of what a completely and utterly immoral and amoral life looks like. Indeed, what Evil looks like. But I also learned a valuable lesson that I have seen repeat itself time and again: If a subordinate is going to take on his boss, the subordinate is almost always going to come out the loser regardless of how right he might be or how incompetent or unethical the boss might be. You are simply viewed as a disloyal subordinate - which, in the eyes of management, is approximately like having leprosy.