When they either know that what they are told is wrong or it is against what they know to be true. The questioning of authority is not in and by itself wrong it is the insubordination of not doing what they are required to do when it is requested. If a supervisor tells you to rob a bank you know this to be wrong and as such you don't do it unless you want to go to prison. If you are in the military and are told to attack and kill the enemy then you do as you are told given the conflict. If a military official tells you to kill your neighbor because the neighbor isn't liked then you would question the authority because the neighbor is not a military combatant but someone that is not liked by the officer. A lot of things you will encounter in life are not clear-cut. This is why one must have a clear understanding of the world and the consequences of one's actions. Even if told to do something by someone that has power over you, will not exonerate the act if the act is not legal or a morally correct action. The excuse, "I didn't know" is not an excuse! Learn!
