No there weren't a "lot" of legal mistakes made by Justice Camp. And this trial constituted the only time his judgment was called into question.

As to your second point, I agree. It's not too much to ask. However in this case, for whatever reason, the judge didn't update his knowledge. He acknowledged that lack and, of his own volition, sought additional legal instruction in law and gender-sensitivity as it applies to that.

Your position is that when a judge makes a mistake, sincerely acknowledges it, and takes steps to make sure such a mistake doesn't happen again, he or she should still lose their job for it. Under a Draconian scheme like that, why would any lawyer be willing to become a judge?