His family challenged the school's decision and took the case to the High Court in Wellington.
On Friday, Justice David Collins ruled in his favour. Justice Collins said the decision by St John's College to suspend Lucan was unlawful and the condition imposed by the school's disciplinary committee that he could return after getting a haircut was unreasonable.
Suspension is a bit of an excessive punishment for a teenage boy who refused to cut his hair, but it is clear the youth needed to he held accountable.
Lucan had signed an agreement stating he would follow the school's rules and some of those rules were about appearance and what was acceptable for school.
If you sign a contract, no matter what it is for, you are obliged to follow through with the contents of that contract.
Workers who did not follow their contractual obligations could find themselves without a job. These matters have serious consequences.
I can understand the school's concern that this could prompt other students to feel like they are able to bend the rules to suit them.
However, Aquinas College principal Ray Scott said he did not believe it would "open the floodgates".
He said rules about appearance, including the length of hair, were about safety and were about maintaining a neat appearance.
My concern is that this could be teaching teens that even if they have signed an agreement, there's ways around the rules.
Is this what we want our younger generation to grow up thinking? They need to learn there's consequences for their actions, both good and bad.