i highly doubt there ever is going to be a need for it in the matter your thinking of. the chances of actully getting into a fight with another magic user on the street are very slim. seeing how most of them, not all, follow some sort of moral code. not all of them fallow the threefold law. i myself, go along with the lines of " well whats the potential loss, if long term it somehow may lead to a death, than i wont, however if its going to ruin 50 or more peoples day oh well they can get over it.
yes potential is one thing,ego is another.
humilty is a lesson that needs to be learned by everybody. the kind of humilty that stands out as a characteristic as you as a person.
Also get over the judgment thing, the moment your born on earth your being judge, and from then on your being judged.