One sometimes hears the idea that justice trumps other considerations. There is a sense in which this is true, but it's not a very interesting sense: ultima facie duties of justice trump other considerations--but they do that not because they are duties of justice, but simply because they are ultima facie duties. Other ultima facie duties--say, ultima facie duties of beneficence or of chastity--also trump other considerations, as that's what we mean by saying that they are ultima facie duties. (One might have some worries here about real dilemmas. But one had better not say that in real dilemmas the ultima facie duties of justice trump other kinds of ultima facie duties, since that would contradict these other duties being ultima facie.) I suppose one could think that only justice gives rise to ultima facie duties. That might be true but only if one has an expansive unity-of-the-virtues kind of view of justice. And that expansive view also trivializes the trumping thesis simply by taking all the other kinds of considerations under the umbrella of justice.
And it's just false that all considerations of justice trump all other considerations. Considerations of justice range over a full spectrum of strength. For instance, there are very weak considerations of justice: whenever I see someone having done the right thing, I have a reason of justice to praise, and whenever I see someone having done the wrong thing, I have a reason of justice to criticize. But these reasons are typically extremely weak, being easily overcome by reasons of social propriety. ("Good for you, you didn't cheat on the test" isn't very appropriate, nor should I criticize every driving infraction I observe a friend making.)