I also have first-hand experience, albeit a decade-plus in the past now, but that matches how it was at my school. They only got involved when there was violence, and a "zero-tolerance" policy meant they punished you for getting assaulted even if you didn't fight back (fortunately, no one at my school realized you could get someone you didn't like suspended by doing a hit and run and turning yourself in).

First. Hand. Experience.

With both options