What I can say is that if your child aware of unfairness, don’t make light of it. If you stick up for an authority who is wrong, it will distance your child from you and futurre Rabbaim.
As a child he looks up to his Rebbe as a great Talmid Chochom. As he grows up, he looks back at his Rabbaim in a different light, although he, hopefully, learned to respect his Magidei Shiurim. At that point, a normal child will be able to look back at mildly unfair behavior without considering it a failing of Yiddishkeit.