That means you haven't been to the concert on Assembly. There were hundreds of mistakes and technical problems (which is ok for the live performance unless you're not the symphonic orchestra). They recordered every instrument separately and later re-recordered what is needed later, mixed, so that fixed studio mixing is what you hear on the video, but that wasn't there on the show.
If you release a live-video (incl. concert dvd) you HAVE to do that.