What does this teach other students?
Lots of good things. Non-violent civil disobedience is appropriate in some situations. Standing up for your rights is important. Everybody deserves a fair hearing, not just an arbitrary decision based on who's got more force on their side. We live, or certainly should be living in a nation of laws, not "do as I say or else."
It is always good to recall that the founders of our nation refused to listen to the colonial Governor, the British soldiers, and even the King himself.
Please explain the constitutional right to continue talking on the phone in the middle of class, especially when instructed to stop...and the right of the other +/- 25 students to waste the rest of their day.
We will not agree on this. Teenagers are sent, under the authority of their parents, to a school where they are to be
under the authority of school leaders. This authority stands unless there is some extraordinary circumstance where authority figures request illegal activity.
This student was asked to conform to standard rules of school conduct. This is appropriate and is not grounds for civil disobedience.