So *forgetting the priest*, who is really more in the wrong here - the guy up front doing the distracting, or the people for allowing it?
That is my question.
1) The guy should have refused to do it, that would have been the right thing for him to do.
2) The people should have refused to let it happen, stopping it as soon as they saw what was going on, that is the right thing to do. No need to be violent or overly dramatic about it, just go tell the guy we don't do that because it is very distracting. My guess is he'd be relieved and go back to his pew happy.
One of these two have to claim the higher fault, especially to let it continue as business as usual.