A man who targeted an Asian family in a road rage rampage received a "manifestly inadequate" jail term, Crown law has argued.
Fraser Milne was jailed for two and a half years for chasing a Chinese-New Zealand family through Awhitu Peninsula last March, causing their vehicle to flip onto its roof.
Two children in the car had taken off their seatbelts out of fear they made need to quickly escape when Milne first approached their car with his pitbull dog, swearing and shouting his dog would eat them.
All five passengers were hospitalised and the youngest child had a skull fracture, scalp laceration, small subdural hematoma and significant grazing over their body.
Milne pleaded guilty to dangerous driving, injuring with intent to cause grievous bodily harm and four charges of injuring with reckless disregard for safety in the High Court last year.
At sentencing, Justice Fitzgerald said while the man had made "abhorrent" racial slurs after the attack she found it was not racially motivated.
An appeal sought by the Crown was heard by Justice Miller, Justice Dobson and Justice Moore in the Court of Appeal at Auckland this morning.
Prosecutor Charlotte Brook said the sentencing judge erred in adopting a starting point that was too low, giving excessive discounts for mitigating features and an excessive discount for his guilty plea.
The court heard the thrust of the appeal was Justice Fitzgerald's decision to sentence Milne on the basis the attack was not motivated, at least in part, by racial hostility.
"The judge considered there was nothing to indicate that racial hatred was the underlying and predominant cause of the offending.
"With respect of the judge the Crown says that that's a misstatement of the statutory test. All that's required is that the judge be satisfied that the offending was committed, partly or wholly, by racial hatred."
Ms Brook said while Justice Fitzgerald said she wasn't downplaying Milne's racial slurs that was exactly what the sentencing judge had done.
"She disconnected his words from his actions by concluding he would have behaved in the same way no matter what the victims' ethnicity was."
She said there could be no dispute Milne held racist views and that, through the way he hurled vitriol at the victims' that day, his views contributed to the attack.
Ms Brook said the man's lawyer Mark Ryan had made a "rather disturbing submission" that racism is a hallmark of youth.
"In my submission, this court simply cannot accept that young people are racist by nature or more likely to say racist things. There's just no logic to that reasoning."
The prosecutor told the court it could look no further than to what Milne had told police to gain insight into why he attacked the Chinese-New Zealand family.
"The most revealing comment, which might appear to be benign at first blush among the litany of racial stereotypes, was what Mr Milne said to police that when he saw the victims were asian he asked himself 'what are they doing all the way out here?'
"The premise of that question is that Asian people do not belong either in New Zealand or the area of New Zealand where Mr Milne was. That othering, if I can put it that way, is sinister and it is racist."
Ms Brook said an appropriate starting point for such an attack was six and a half to seven years' imprisonment with a 20 per cent discount.
She told the court it was "nothing short of miraculous" the victims hadn't been killed or more seriously injured when Milne struck the vehicle with the intention of driving it off the road.
Mr Ryan said Justice Fitzgerald's adopted starting point was suitable for the case and its circumstances.
He told the court while his client had acted "appallingly and atrociously", he was young and thought the victims damaged his father's car.
"This is not a person who is acting rationally. This is not a person with extensive life skills..and people say things that they spout off. It doesn't meant to say they've got an underlying intention."
Mr Ryan said his client was 20-years-old at the time of the offending and recovering from methamphetamine use.
He told the court, as he did at sentencing at the High Court, that the outcome would have been the same no matter the victims' ethnicity.
"It wouldn't have mattered who was in the other car. It wouldn't have mattered if it was a car load of nuns, with respect."
The Court of Appeal has reserved its decision.