It's not the case that doing good makes one's bad deeds less bad.

In isolation, I think that quoted line is (morally) correct, though. Moral conundrums abound, I've got a list of several hundred written down somewhere, so being hardline about everything is just a way to be more aggressively wrong.

(I'll note that the question of whether to punish somebody is separate from the question of whether they did wrong. What's punishment? It evolved alongside payment and vengeance, and now it has extra functions, such as deterrence, and taking power away from people who are statistically likely to do further bad things. It's related to the paradox of tolerance, and it's a desperate measure. It's not rational. The world should not run on punishment! The rational thing to do is talk everything out. But since that doesn't happen, punishment is the suboptimal but practical solution to conflict. When it comes to punishment, we do take people's good deeds into account. Don't ask me how that should apply to Huang, this is just a footnote.)