I personally would not do this, but suppose someone said "Say what you want about Rebbe Nachman, but you can't deny the truth of where he said xyz." How do you think Rabbi Brody or any other Breslav adhering Jew would take a statement like that? I'm not a Breslav adherent, and I would be insulted by it. So why is this defamation allowed to pass, and in fact customary, when people speak about the great Rabbi Kahane?