A leading member of the Law Society has dismissed a call for a law change by the father of Stephen Dudley who died after after being assaulted at a school rugby practice.
The 15-year-old had an undiagnosed heart condition and died after the attack in June last year.
His 18-year-old attacker was on Thursday discharged without conviction at the High Court in Auckland on an original charge of manslaughter because he was not aware of the condition.
However Stephen's father Brent Dudley said his son would not have died if not for the assault, and he will campaign for changes to broaden the level of culpability.
The assailant's lawyer, John Munro, said the one punch delivered to the neck and three or four to the torso, were at the lower end of the assault scale.
Former Crown prosecutor and convenor of the Law Society's criminal law committee, Jonathan Krebs, said it was a highly emotive issue and one that would be tricky to address.
"It's a very, very difficult issue," he told Radio New Zealand's Morning Report programme. "In our criminal law what's important is what a person knows and intends at the time they commit an act. If you don't know about it then you can't be responsible for it."
Mr Krebs said laws giving judges the power to discharge a person without conviction should not be touched either.
Anger in court
In court on Thursday, Brent Dudley 's anger and grief erupted as Chief High Court judge Justice Winkelmann discharged his son's attacker without conviction.
Mr Dudley swore and called the justice system a joke, and told Justice Winkelmann that she was actually sentencing his family, not the teenager. The Dudley family left the court before Justice Winkelmann had finished her sentencing.
In sentencing, Justice Winkelmann said Stephen's undiagnosed heart condition made him vulnerable to traumatic stress and it was impossible to tell what had caused his death.
"I do not take into account the fact that Stephen died after the fight. "There is no suggestion that any of the blows struck caused injury, in and of themselves. Assessed in that light, these were punches thrown in the context of a schoolyard fight."
The 18 year old had faced a charge of manslaughter but that was downgraded due to Stephen's pre-existing heart condition.
For the teenager, lawyer John Munro said his client was sorry and had spoken to young people at his church.
He had also offered to take part in a restorative justice meeting and ifoga - a Samoan custom where the family of the offender waits outside the house of the victim and begs their forgiveness - but the Dudley family rejected that.
He said his client hoped to be a PE teacher and a conviction could harm his chances of working with children.
Another teenager, aged 16, has already admitted assaulting Stephen Dudley and he was also discharged without conviction.