networkn: But you can't legally be punished for a crime you have not been convicted of.
Do these boys need to be convicted - which means "declared to be guilty of a criminal offence by the verdict of a jury or the decision of a judge in a court of law"? Are you seriously suggesting an actual criminal trial is necessary, and that the school can only punish these boys if proven guilty by the New Zealand justice system? Is your name Shane Kennedy? Schools, and parents, punish children in their care for bad behaviour all the time.
And...
6FIEND: The boys do not dispute any of the reported facts around the incident. (I.e. They openly admit that they did it and that they know that what they did was wrong/stupid/illegal.) There are confessions, eye witnesses, video evidence, and formal police warnings.
They have admitted they rode the baggage carousel into a restricted area - what more is required? Even if you mean they need to be proven guilty by an investigation (not a trial) the boys have in effect plead guilty, therefore an investigation is unnecessary.