Mr Harrison said that would be fine, but asked whether Lucan could return tomorrow to give Mr Melloy time to speak with college staff about the situation.
Lucan, with his hair tied back, and his father were both at yesterday's hearing.
Mr Melloy said it would be a "disaster" if Justice Collins struck down the school's rules, which the school's community had put in place, as that would result in major repercussions across the country with other students not wanting to follow school rules such as wearing a uniform.
When Mr Melloy initially asked Lucan to cut his hair, he refused, and asked the principal to speak with his father.
"Straight away you've got a refusal of the principal's request," Mr Harrison said.
"We've got continual disobedience."
His defiance of the rules was "harmful and dangerous" because it could influence other pupils who could think Lucan's actions were cool, Mr Harrison said.
Lucan's lawyer Jol Bates told the court Lucan followed in the footsteps of human rights defenders including Martin Luther King Jr and Kate Sheppard, who challenged authority on a justified basis.
The school's rule around hair length was that it needed to be off the collar and out of the student's eyes.
Lucan would wear his hair tied up, off the collar and out of his eyes, so was therefore abiding by the policy and should not have been suspended, Mr Bates said.
"We're not splitting hairs."
Lucan had been at the Catholic school for three years with the same hairstyle, Mr Bates said.
He had curly hair, which if cut, would become "boofy and turned into an afro", he said.
"He's simply not comfortable [with that]."
His hair was not a health and safety issue, nor was it a distraction to other students, Mr Bates said.
He said Lucan was following the example of other human rights crusaders.
"Certain people in history have stood up to laws that they don't think are just and that was the context of that comparison," he said.
Outside court Lucan said he was "pretty happy" about going back to school this week.
"I'm looking forward to going back ... it's been pretty stressful."
He had a lot of friends supporting him, he said.
It was "overwhelming" that the process had made it to the High Court.
At no stage had he considered cutting his hair, but there had been a lot of strain around the issue. "I had a lot of fights with dad."
If the judge ruled against him, Lucan said he did not know whether he would decide to cut his hair or move to a different school.
"I'll decide that then."
He was no rebel or human rights crusader, he said.
Lucan's father said they got a fair hearing and even if they lost the fight, it was worth it.
"It was about Lucan being able to express himself."
He would leave it up to Lucan to decide what to do if the ruling did not go their way, he said.
This year, Lucan received a bravery award for for helping to save two women from drowning off a Napier beach in January last year. He was also in the school's 1st XV rugby team.
Neither of those factors were taken into account when Lucan was suspended, Mr Bates said.
Justice Collins reserved his decision.
Troy Battison appeared on TV One's Seven Sharp last night and said he was interested only in Lucan returning to school and to "everyday life, to carry on with his education and become a fine young man".
Mr Bates also appeared on the show and said the family was concerned whether Lucan received a "fair go" with the principal.
He said suspension was "pretty brutal", considering schools had other disciplinary options for "recalcitrant" pupils.
Mr Melloy said he did not want to comment on the case.