Not every black girls’ mouth is the reason why someone assaulted her. My theory about that entire incident is the teacher escalated it because he was power-tripping.
He was going to teach her a lesson for not obeying him. By the time the teacher and the principal are there, she’s not doing anything but sitting at her desk. That’s it.
This girl — and she is a girl — could have been your little sister, your niece, or your young cousin. Placing any level of blame on her for causing this incident is ridiculous. Had it not been for the teacher wanting to throw her out of his classroom and not look soft in front of the rest of the class, this situation would have remained a simple interaction between a teacher and a disobedient child.