Probably a good thing they "attacked" him before the idiot started a riot - there's a time and a place for everything, he should have petitioned to see the cardinal a week before the parade - by the time MV comes in trying to start his drama, it was obviously too late.
I mean what did he expect - that the cardinal, who probably personally pushed for the queers to be in the parade, was going to actually say anything worth hearing? He's lucky he didn't get beat up by the crowd.