IHC says the illegal exclusion of a boy with special needs from an Auckland secondary school is not an isolated incident.
The High Court on Monday overturned the 14-year-old's exclusion from Green Bay High School because the school did not consider all the facts involved.
The boy had walked out of a lesson, struggled with a teacher over a skateboard, and then closed a door on the teacher, jamming his arm and striking his head.
IHC's director of advocacy Trish Grant says some schools are excluding students instead of helping them.
"There is a worrying trend that many schools resort to disciplinary processes in the absence of putting in the good support as early as possible.
"In this case this young man arrived at his school, it was clear from the outset there was a lack of the support that could have made a difference."
Trish Grant says the case is a powerful reminder to schools.