I suggest a week end seminar for concealed weapons. Gun are a greater deterrent than any jitsu I've seen or the modern age. In fact, jitsu in all honesty is an outdated means of self defense.
Maggie.... Are you suggesting that he send a high school kind to get himself a permit to carry a weapon at school in order to end his bullying problem?
To the OP it seems like you handled it well. I would definitely talk to sensei about it so he also can help this young man out. In fact aikido may well serve him in that as he gains self confidence he will carry himself differently and not be so afraid of conflict and his bullies may well decide to leave him alone. Aikido will help him to defend himself. just maybe not in the ways he is currently thinking it will.