Defacing school property is disrespectful.
Martin is at the principal's office at school, where the principal tells him he will call Martin's parents and tell them he's been skipping school.
Martin wants to emotionally react to the principal's statement.
Martin starts to cry and tells the principal his pent up feelings about why he's been skipping and how he promises to do better.
Martin runs out of the office angrily and slams the door so hard that it breaks the office window causing a thousand dollars of damage.
The principal is happy Martin is being open about his situation and is happy to see Martin share his feelings.
The principal is shaken by the violent crash of the door slamming and the glass breaking and is temporarily terrified.