Obviously the mom has seen the negative behaviours and may very well be trying to see if she can work with him to the point he would be ok in care. Going back to a situation where he was negative before might actually have the opposite effect on him and make him revert to the way he was which will mean starting over again from square one when he goes back to school. I would strongly be suggesting she get a local teen to work one on one with him for the month - ideally someone working on a developmental social work degree or something similar.