If Nikolas Delegat were poorer he would have received a harsher sentence, the Police Association says.
But a Dunedin barrister has rejected the ''outrageous'' claim, saying the sentence matches the offence.
Delegat, 19, the son of a multimillionaire wine magnate, was sentenced in the Dunedin District Court on Monday to 300 hours of community work and a $5000 compensation payment.
The former Otago University student had been drinking heavily in Dunedin in March last year when he became enraged and assaulted Campus Watch staff member David Ogilvie.
He then kept punching Constable Alana Kane after she had been knocked out.
New Zealand Police Association president Greg O'Connor said if Delegat had been from the ''other end of the socio-economic scale'', the sentence would have included jail time, or something closer to it.
A ''high-powered lawyer'' could help someone get a lighter sentence, he said.
The sentence had caused ''general disquiet'' among some police officers in Dunedin, especially given the severity of injuries sustained by Const Kane.
However, Judge Kevin Phillips needed to be commended for resisting the ''considerable pressure'' to grant name suppression and discharge without conviction, Mr O'Connor said.
Mr O'Connor hoped Delegat would complete his community work with ''mainstream offenders'' on the same conditions.
He feared, though, that Delegat's legal team would advocate for their client to be given special treatment.
Mr O'Connor said the services of ''good lawyers don't stop at the sentencing''.
A ''short sharp jail sentence'' would have had a bigger impact on someone with a ''sheltered'' background, Mr O'Connor said.
Dunedin barrister Anne Stevens said the claim Delegat had bought justice was ''outrageous''.
She had been a lawyer for 29 years and the sentence was ''entirely consistent'' for the type of offence, committed by someone with no previous convictions and otherwise good character, and who had pleaded guilty.
''It's nothing to do with his parents' wealth, it's nothing to do with the colour of his skin; it's to do with his culpability and his character.''
The conviction was a ''serious outcome'', Mrs Stevens said.
''He wants to sail in other parts of the world and it will be a big burden for him.''
The sentence had nothing to do with Delegat's choice of lawyer, she said.
''Any number of lawyers in Dunedin would have achieved the same result ... some of them, I dare say, would have got a discharge.''
Acting area commander Otago Coastal Inspector Kelvin Lloyd said he would not comment on the possibility of the police appealing the sentence.
Insp Lloyd said Const Kane was ''very grateful'' for the support and concern from members of the public and she was focusing on her return to work.
It was the second time Const Kane was the victim of an alcohol-fuelled attack by a young man.
In February 2011, she was knocked to the ground by Jamie Trev Cooper-Siggleko, then 22, when trying to arrest him.
Mr Cooper-Siggleko and his 15-year-old brother punched Const Kane in the head repeatedly. Her injuries, as later detailed by a doctor, included a bleeding nose, damaged wrist and apparent loss of consciousness.
Const Kane had been called on by fellow female officer Const Kristyn Adamson for assistance after Const Adamson did a breath test of Mr Cooper-Siggleko during a bail check in Dunedin. He failed, which was in breach of his bail conditions.
He tried to persuade Const Adamson not to arrest him and then he and his brother started abusing her before Const Kane arrived.
Mr Cooper-Siggleko, sentenced to six years' jail, served three years and five months in prison for the assault and a benefit fraud charge.
Delegat's lawyer, Auckland barrister Mark Ryan, did not respond to questions yesterday asking if the sentence would be appealed.
In court on Monday, Mr Ryan said his client was willing to undertake community work in conjunction with police and local authorities to address the ''out-of-control drinking culture'' at the University of Otago.
University proctor Dave Scott, when contacted yesterday, said there was a nationwide alcohol problem where large groups of young people congregated.
The university and Campus Watch were trying to address the problem in Dunedin, he said.
''Thanks to our well-resourced efforts to keep the campus environment safe, we have made good inroads into behavioural problems arising from alcohol abuse around the North Dunedin area in recent years.''
Most of its student population were law-abiding, focused on their studies and not generally known for violence, he said.
In a statement released to the New Zealand Herald yesterday on behalf of the Delegat family, Delegat apologised for the harm he had caused.
''Nikolas takes full responsibility for his actions that night,'' it says.
''He attended a restorative justice conference where he expressed his remorse, and he again apologises to the police officer, university security guard and all others concerned.
''Nikolas was in the first two months of his university study away from home in Dunedin.
''He made a bad decision in the heat of the moment which caused considerable harm to those affected, which he regrets.''
-Additional reporting NZ Herald reporters