They didn’t have a real PA system beyond the Shea PA, which wasn’t anywhere near adequate for concerts. Seems like I remember commentary that between the size of the stadium, and the screaming, that nobody could hear them. The new 4K concert film will no doubt be the definitive record of the event.
They did a 13 minute set at the Pittsburgh Civic Arena, a building that was originally built for an opera, but quickly abandoned due to lousy acoustics. Fans felt cheated.