Government communications adviser Joel Benjamin Ineson says he didn't realise he was holding a glass when he threw a punch that caused permanent disfigurement.
The Christmas Eve punch in an upmarket Merivale Bar in Christchurch injured the ear of the 21-year-old man he had argued with.
The man's Christmas holiday was ruined while he had stitches and ongoing medical treatment and he has been left with a disfiguring scar on his ear.
Christchurch District Court Judge Quentin Hix released Ineson on supervision for a year, ordered him to abide by a nightly curfew under community detention for four months, and ordered a $2000 emotional harm payment.