So whether or not the Bishop confronted them in private, to confront them in public given their previous public stand would be entirely appropriate.
Besides I'm not sure this bishop see these guys as true servants of the church. He may very well see them as infiltrators. If you are trying to get a disruptive employee to resign, and make an example for the rest of your employees. You might very well call them down in public.
I disagree. Fraternal correction is best not done in a public way.
If Olmsted's philosophy is like Patton's, that he'd rather be feared than loved, he's well on his way to accomplishing that.