Sorry if I implied that the school staff 'wanted' your DS out-- that's definitely not what I intended. More along the lines of what you've stated-- that they wanted what is best for him, and that strategic failure might well have been it at that point in time.
I hear ya about boarding school. Still-- probably doesn't hurt to examine the possibility and see if there is financial assistance, right?
Ahhh-- deeply unfortunate that one parent is seeing PS placement as "punishment" for malfeasance as opposed to "a better placement for right now."
Maybe HS can offer him dual enrollment-- though he may well have shot himself in the foot there with his recent performance.