Three were excluded from class, something the International Education Appeal Authority criticised.
Justice Ellis said there was no error in the International Education Appeal Authority's findings and said the college "acted unlawfully in expelling [student] L and excluding [student] E on the grounds of gross misconduct".
The contracts between the school and the boys' parents could not "override the Act or give Tauranga Boys' College the right to terminate (and effectively to expel and exclude) on grounds that were inconsistent with the act", she wrote in her decision.
She conceded that the authority did breach natural justice by failing to give the school the chance to respond to its findings before releasing its decision but said there was no merit in any of the other grounds of review.