Finding the line between being respectful, and calling someone out can be tough. When the two involved are of different class or rank, the line can be even more difficult to determine.
Here's an example. You and a few of your peers are doing your jobs, and on this particular scenario, your boss is present and lending a hand. Because he's everyone's boss, he is naturally looked to as a leader in the scenario. As you all finish up, he does something out of place or out of protocol. What do you do?
This short scenario paints a picture of the factors at play here. Do you speak up? Of course you don't want to embarrass him or disgrace his rank in front of your peers. However, if you walk away silently, your peers will accept your bosses actions as appropriate going forward. It could be a safety issue, it could be an expensive issue, it could be any number of wrongs, but what's important is to set it as a right before it gets set in stone.
Anyone from Andy Griffith to Beaver Cleaver could see the right thing to do here, it needs to be called out. There should be no doubt there, where the finesse comes is how you go about it.
Unfortunately, in the culture of some organizations, it's unforgivable to question the leader, at all. In some large corporations or military scenarios, this isn't possible. Ideally however, you could set the organization in the right direction by being the example in this scenario.
Set it straight, do so respectfully, and ultimately teach everyone in the circle a whole series of lessons. We don't do things wrong around here. Our leaders are ok to be challenged. We treat each other with respect. We speak up. Experience is valued, not just rank.
Hopefully, you'll have such class that your leader will respect you even further. Your peers will look to you as a leader. The balance here is the difference between happily ever after with your boss and peers, or the rise of a renegade revolution. Don't divide, unite. Do it with respect.