There are a couple of videos doing the rounds, one is of an older man walking around very wet, clearly angry, he’s the one being called “Mr Miyagi”. Another video shows another younger man sat on the side of the fountain who’s pushed in.
But yes I have seen it suggested that they could be workers/residents of the area essentially serving the supporters.
A complete shambles anyway. I could kind of understand it if it was another set of Barca fans and it was “lads” banter between supporters. It would still be moronic of course.