Chunn's lawyer Petrina Stokes said her client had previously worked as a writer on "promotional activities" and had also written a book, the publisher of which had folded during the global financial crisis.
He had spent the last year on bail living on Waiheke Island and more recently had completed 12 sessions of anger management.
"The fact is these proceedings have really sort of stopped his life in its tracks," Ms Stokes said.
The court heard how Chunn had previous driving convictions from 1995 but Judge Fraser said they were not relevant.
"To find future employment, you'd be obliged to declare [a conviction] and it might well be an employer is not interested in looking behind what happened," he said.
The judge ruled the negative consequences of a conviction to Chunn outweighed the gravity of the offending and a discharged him accordingly.The defendant was, however, ordered to pay court costs of $130.
"You get this opportunity once and I assume you're an intelligent person and have learned a valuable lesson through all this," Judge Fraser said.
"You now know, and I'm sure you did before ... that picking up a mop and hitting someone is not the appropriate way forward."
Mike Chunn, who was made an Officer of the New Zealand Order of Merit in 2002, is the chief executive of the Play It Strange Trust, set up to encourage young Kiwis' musical endeavours.
He has not commented on his son's court case.
