two things i've noticed
firstly, the title of the headline
High school girl describes moments when 3 officers pinned her at school
and in case you don't get it
High school girl describes
the news story that was linked in OP is coming straight from the girl's mouth. no doubt that she's gonna give us inaccurate information at some point or another.
secondly, the video only shows what happened after she was tackled, not what happened before. there's almost no way of telling exactly what could have happened before this. the main source we have to go off is the article in OP, which, is what I just talked about above.