The judge said — "by a small margin" — that outcome would have been out of all proportion to the gravity of the offending.
Johny's online CV states he has worked as a "document controller" on multibillion-dollar projects in Japan, Canada and Saudi Arabia.
He came to New Zealand, the court heard, expecting to find similarly well-paid work.
It was a significant blow to his self-esteem when he struggled to get employment here and instead spent his time looking after the children, Judge Smith said.
On December 8 last year, Johny and his wife argued.
He went into the bedroom, where she was and pushed her on to the bed before punching her in the nose.
It caused the victim's nose to bleed and left it swollen.
The defendant initially told police it had been a slap rather than a punch that had done the damage but later pleaded guilty.
While Ms Henderson emphasised Johny had no previous convictions, police prosecutor Stewart Sluis, who opposed the discharge without conviction, said it appeared not to be the first violent episode in the home, from the victim's statement.
Mr Sluis said a conviction was a fair result and would allow Immigration New Zealand to be fully informed when it made a decision on the defendant's status.
The judge said the gravity of Johny's offending was low to moderate.
She took into account the fact the victim supported his bid to maintain a clean record.
Johny was ordered to pay court costs of $130.