Call their parents. Move the class. The class is what, an hour long. They can deal with a loss of an hour. How much of distraction has this now become for the school? Not including lost time and money.
Call the parents? Why? How do you know that situation won't get even worse? How do you know you can even reach the parents, or that the parents will be able to get to school within a few minutes?
This hasn't become a distraction for the school at all, the school did nothing wrong. I don't know if the officer applied too much force or unnecessary force (I don't know without the details), but the school did absolutely the right thing. Having one of the teachers or school administrators physically restraining / fighting the student is an absolute no-no for many reasons, so calling the cops to deal with a student that simply refuses to comply is the right thing to do.
The idea that precious snowflakes can't be touched for any reason when they refuse to do what they have to do is absurd. They are no different than any other citizen. If you are given a lawful order by an officer you can either comply or be physically forced to comply. That's even more important in school because it's supposed to be a safe learning environment for the students, and such disruption impacts other students.
Physical force should never be the first resort, but it absolutely has its place.
The issue here isn't whether force should have been used, the issue appears to be how much force was used.