John was appointed a District Court Judge in 1990 following a 16-year career practising law. He was a member of the New Zealand Parole Board between 2002 and 2016. John retired from the bench in March 2022.
John played basketball for New Zealand between 1969 and 1981, captaining the first side to beat Australia in 1978. He has been the patron of Basketball New Zealand since 2012.
In other sports, John played cricket for the Otago Brabin Cup and under 23 sides. He also played for New Zealand Universities, scoring a century on its 1969/70 Australian tour.
John was inducted into the Basketball Hall of Fame in 2017 and the Maori Sports’ Hall of Fame in 2019.