Totally possible. But if this had been the case, I feel like someone would've come forward by now with that info—like another student, or even a bus driver, who witnessed the bullying or heard a snide remark, etc. Then again, given the huge publicity this case got, maybe those potential witnesses don't want to be connected to that, even after all this time.I wondered about bullying on the school bus? I experienced it myself resulting in eventually having to transfer to a different bus. In this case though it seems it was from time to time and I'm not aware of any accounts of bullying.
For that reason, I don't think bullying on the bus or even at school was a factor. And it couldn't have been bullying on the street because then he would've always taken the bus back home.