One of the main (if not the main) point of his speech was that the organizers of this event then went ahead and photoshopped the kol Korah and it was a big bizayon.
Is that true? Any shmoe probably went ahead and did this. Why make out the organizers as servants of the yetzer horah? And that this whole thing was one 'egel hazahav'?
Highly unlikely.
He was very upset about the Maacha and the cops as well etc.. from what I hear it only became a matzav/ the crowd grew exponentially after the cops were called (by a certain person והמבין יבין)
..besides what makes him think the organizers of the event arranged the kumzitz... (It seemed from the videos like a mob mentality more then anything else not something you can blame a specific person..)
Being that there were differences of opinions and even changed opinions reportedly because of pressure, a real explanation is due.. not just a "you gotta believe" especially today that sadly Rabbinim are fed all sorts of information...
His explanation that in the future it's gonna be a mixed concert...
Regarding that such a thing has never happened in Klal Yisroel.. um for the last (10?) years this has been going on in EY under the name kumzing or kumtantz.. iiuc with the bracha and support of R Aron Leib.. (besides for R Meilich Beiderman, R Mota Frank's kumzitzin)