First of all you made it sound super complicated to teach kids without bringing books and rewriting chalkboards. You're like the infomercial where the person not using the infomercial product is a bumbling retard that fumbles piles of underwear at K-Mart because they didn't use their Chipotlaway.
OK back to reality. Let's compare 2 options:
1) removing the students *purbeast0 no likey
2) getting violent with the girl *purbeast0 likes this one
BOTH result in the class being severely interrupted. It's too late to prevent that by now. You realize that, right? You think after watching what happened with the cop, that the kids are just gonna calmly go back to their math work and concentrate?
Yes, the girl is having a hissy. She should get suspended. If it happens, expel her and permanently remove the problem child from the school. The kids all said she was showing off. So if you go with option 1 and remove the class, there is nobody left to show off to. Her reason to resist is gone. More than likely she gives up non violently and you can suspend her. For the rest of her life, it is probable that she never pulls that shit again. Problem solved non-violently, cop not fired, school not sued. For the price of interrupting the 2nd half of a single class on a single day, every kid who was in that room knows not to pull that again.
OK, so think option 2 now. The class gets interrupted. Cop gets all rage-y and violent. Cop gets fired. Cop gets sued. School gets sued. You just know the unruly idiot child is going to win money from the taxpayers, right? What child in that room just learned NOT to do what she did? They all learned exactly which buttons to press to get their 10 minutes of fame and $100,000 payout.
Which option is more likely to result in less future disruption? Which option awards my taxpayer money to attitude child? Is it possible that there are options that DON'T involve using cop-rage to fix the issue?