I wasnt talking about the original matter. I was talking about how misnagdim forged bishmo statements against Chassidim and he denied it.
As far as that is concerned, first of all he was a Tzaddik and an Admur and a Gaon so to say he was a nogeia bidavar may be one thing, but to say he made a misjudgement on a matter that is relatively easy to determine (normal conversation (and the fact that he was received in the first place for a conversation shows something too) is another. Second of all this was a private letter (also it was to his son-in-law the Tzemach Tzedek to whom it was important that the facts be straight). Third of all he was masiach lfi tumo. Fourth of all this letter was not published until around a hundred and fifty years later. Fifth of all what does being nogeia bidavar have anything to do with the possibility that notwithstanding the undeniable machlokes there was a gadol who wasnt involved or had a different opinion, especially considering the *fact* that there were Gedolim who were soon going to, if not already were respecting, collaborating with, etc., Chassidim. And especially considering the *fact* that there were many *big* Rabbonim, some of which were even originally *Misnagdim* who *became* Chassidim.