Hmmmm, if he is throwing things so someone might get hurt, you have to stop him from doing that. Remind him that he is a better person than to behave that way.

Aside from that, be compassionate and discuss with him how he feels and why. Perhaps when he has calmed down a bit you can discuss the sorting system, and whether it is fair, and how it can be improved, what consequences being sorted into one house over another has, and if a student who is sorted into Hufflepuff can still show the courage associated with Gryffindor, and so on.

Do not make light of his emotions. Be compassionate, but do make clear that certain behavior is inacceptable because it puts others at risk. smile