You shouldn't hurt people by pushing them over.
Joe was walking down the school hallway and Steve runs into him on purpose.
Joe wants to retaliate against Steve.
Joe reports Steve's actions to the hall monitor who in turn reports to the faculty.
Joe pushes Steve over, causing Steve to fall on his backpack and break everything inside.
Steve gets detention and in fear of getting detention again stops running into Joe.
Joe's parents have to pay for Steve's things and ground Joe for a month.