Make no mistake, if the CC consider ANYTHING may constitute a hazard to the aircraft, and that may include further provoking a drunken passenger, they are justified in taking such measures as they see fit to contain the situation and, as captain, I would back them up.
Does that include feeling the fire of alcohol consumption? What do they hope; the pax will go to sleep before they explode? If taking social photos of you and your friends on holiday is acceptable, when does taking a photo become unacceptable. If a pax refuses to stop photographing and the airline tries a prosecution under ANO, claiming that the 1 year experienced Purser was using what they believed to be the wishes of the captain, I would not be surprised if the judge/magistrate was bemused. What do you expect to happen if said photographer was a journalist for a national major newspaper. Do you think they would cower meekly? I think it is not quite so black & white as some make out. How many seats away from the melee is antagonising the situation and how far away is not?
Where I live all buses have on board cameras. I don't know if they transmit live or record. Might a/c move to the same?