Over on ChabadTalk, I was persuing a long thread on the subject of whether or not Tzadikkim are infallible.
One poster said:
Did Hashem ever punish David HaMelech for doing anything wrong? Yes, more than a couple times. Nathan HaNavi went to rebuke David and David said one word - Chatati.
There should be no need to remind ourselves of these Jewish ideas-- that our most G-dly Tzaddikim are still human beings, not all-powerful and not all-knowing, and if they aren't vigilant enough, they can have a yerida (a fall). This is one of the first lessons in the Torah-- that a person on the level of Adam at the highest peak of wisdom and closeness to Hashem, if he is not careful, he can lose his level and fall. To reject these ideas, is to subscribe to a different religion.
In response to this, another poster responded (emphasis mine):
even if the general point you make is valid, about Tzaddikim erring etc, with which i disagree, the examples you brought are from Chazal and Tanach which seems to say the Tzaddik erred etc.
How relevant is this to our discussion, where ploni almoni wishes to give HIS own opinion that This or that Tzaddik, in his opinion erred, even to the point of saying his own "alleged" Rebbe erred. You call that another religion. I say that saying that about your Rebbe is kefira ( and dont ask me for the source).
Scary, isn't it? Saying that your Rebbe is fallible is not simply in error, but is kefira!