Hmm, wonder why the students who walked out of class, causing a disruption were not manhandled by the SRO like the student who was using her phone in class? Odd that there should be such a disparity in the treatment of children who are equally in violation of school rules? What is the thought process there?
Reading between the lines, I think they had permission to do this. It was clearly an organized thing - the students all walked from class to a specific on-campus area, and after 10 minutes were directed back to class, which they did in an orderly fashion. My guess is, some of the leaders had cleared this and heard the rules: make it orderly, no one leaves campus, disperse when told to. Sometimes, you can seek special permission to have an event on campus. Like mum sales during lunch. And that's why. Because it was a completely and totally different event. One was open defiance that demanded a response, one was a pre-sanctioned event during the school day.