A Dunedin mechanic who punched a man during a household dispute says a judge has ruined his Christmas.

Philip James Marchant, 37, represented himself in the Dunedin District Court on Wednesday, exactly two years after the physical altercation.

Despite knowing the defendant for only two days, the 54-year-old victim offered to provide Marchant with accommodation.

After squabbling about money and a damaged laptop, things escalated to physical violence when the defendant punched the victim in the face. Attempting to follow Marchant, the victim then fell down the stairs.

The victim was taken to hospital by emergency services where he underwent surgery to implant three titanium plates in his face after being left with a shattered eye socket, broken cheekbone and a fracture above his left eye.

Marchant was originally charged with assault with intent to injure but had his charge amended to common assault, further “traumatising” the man.

A victim impact statement outlined the “exceptionally painful” injury which led to problems with the victim’s eyesight, panic attacks, regular blackouts, and a diagnosis of PTSD.

“That one punch could’ve killed me,” the man said.

Judge Michael Turner said the victim was particularly vulnerable as the incident took place in his own home, somewhere he ought to have felt safe.

Marchant said he had “a bit of remorse”, but his main concern was the consequence any punitive measures would have on his family.

“It’s my daughter that will suffer if I can’t leave home at the weekend,” Marchant said.

Judge Turner promptly responded that this was simply “one of the consequences” of his behaviour.

Marchant was sentenced to three months community detention and had 150 hours of community work reimposed for a previous sentence he did not complete. He also faced one year and one day of driving disqualification for other charges.

Due to his sentence of community detention, Marchant was forced to give up weekend employment as a dairy farm assistant in Mosgiel.

The news left him so agitated he stormed out of the courtroom, shouting “Thanks for devastating my Christmas, because now I’ve got no job”.

- Erin Cox, ODT