I don't know whether bullying was a factor in this case, but I do know that no one who hasn't been seriously bullied, stalked, or harassed over a long period has the slightest clue of what this does to the victim. It is utterly ruinous. I could easily imagine bullying leading to justifiable homicide.
Also, bullying has nothing to do with teachers punishing people who "stand out," nor is it likely to happen in classrooms. It is more likely to happen in hallways, stairwells, bathrooms, locker rooms, etc. As I said before, many of the perpetrators are junior sociopaths who are headed for a life of violent crime. They are the ones who should be rooted out of schools--not the Asperger's types, assuming the latter are able to behave in class.