I completely agree with this ruling, in this case, the bully got what he deserved and the bullied kid had every right to defend himself.
Having said that, taking it to the extreme of killing another person is too much. I was bullied when I was in 7th and 8th grade, but after taking three years of intensive self-defense and martial arts classes (Krav Maga and Taekwondo), I beat the living shit out of the guy on 9th grade and afterwards all bullying stopped. Most of the times, all that it takes is to learn how to defend yourself while not taking the abuse constantly.
You've got to consider that in the otherside there's also another human being who has a family and people who love him/her. Sometimes the parents don't know that their kid is a bully (in my case they didn't until he came back all battered and talked to me, my colleagues and the school afterwards) or even if they do and don't act on it, doesn't mean they love him less. Taking someone's life should never be a choice.
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