Before I address this, I need to say that I think you and way too many posters are taking liberties with the word "child" here.
Underage? Yes.
Minor. Of course.
"Child", though semantically accurate here, is framing the context of the situation to fit the narrative of some brute using his might to overpower someone excessively. Correct me if i'm wrong, but isn't this a teenager in a high school? Adolescents (from a clinical standpoint), are not considered "children".
To address your question though, that argument would miss the point. Once she behaves in such a manner, the only way to end any continued disruption is for her to end the behavior. Most of us I believe are in agreement that physical removal of some degree was the only solution. I would say it's not a matter of it being a bigger disruption but a continuation of the initial problem. And again, he didn't pull out a night stick and beat his rent money out of her, he didn't tase her, he didn't shoot her while she was obeying the law minding her business. The only thing i'm critical of concerning his removal is that if the option for another officer or school staff existed to assist him, than that should have been used, because that lessens the chance of injury to everyone.