The underlying act took place off campus; we don't know, but sharing the audio apparently took place at school.  The school should have immediately brought in the parents and first let them alone get to the bottom of things that took place off campus and then address the sharing of the audio at school with dean and parents present. No police, unless after talking it appears that government action is required.

During the last ice age when I was small, adults would have handled this far more adroitly. And I don't buy the reference to in loco parentis.  I am a great believer in it, but this was not an occasion to exercise authority under it.