Accidental bumps are seen as a serious diss in some cultures. Maybe we'll learn more facts soon.
And idiot news readers are saying this might have been the result of a "misunderstanding", as if accidentally bumping into someone in a crowded school hallway should ever result in a violent reaction regardless of understandings, or misunderstandings.
If I had a dollar from everytime I was bumped when \i was going to school?