Maybe the Principal is also scared these day that they could be the victim of an assault by this crowd? Who knows?
If he is going to another school anyway would that matter? I think there comes a time when our kids just have to be protected, that is a parent's duty. Next time & there will be a "Next time" by the same bunch of thugs some poor kid may die & how would he feel then knowing he could have helped in stopping this?
He obviously is scared of repercussions down the track. I believe expensive Colleges are no better & probably some are worse.
Hard choice for you I know, but my best wishes to you.

