It is always a good idea to tell the truth. As long as one maintains good moral conduct, telling the truth will always, eventually, reward the honest person. Being prior service military, I find that being a Whistle Blower is much like being a Blue Falcon. Someone who is always getting their team in trouble for the smallest, most irrelevant, errors. On the other hand, a good team player will try to determine when it is necessary to “blow the whistle”. The two might be one in the same when someone is in a line of work that requires no moral errors such as an FBI agent.
In my opinion, a boss or leader has to lead by example. Personally I would confront a boss with every offense he/she perpetrates, solely because if he/she doesn’t fix their behavior, the rest of the team will surely follow. The consequences of doing so could be anything in a wide range of consequences. It could be as negative as losing one’s job, or as positive as the boss thanking you for keeping him/her in check. Honesty with oneself, one’s team, and one’s boss is always the best policy. It will assuredly reward the honest person.