John was appointed a District Court Judge in 1990. He was a member of the New Zealand Parole Board between 2002 and 2016.
He 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 cricket, he was selected in a New Zealand Brabin Cup (under 20) side in 1968. He also played for New Zealand Universities, scoring the only century on its 1969/70 Australian tour.
He has represented New Zealand Seniors’ Tennis in the Australasian Teams’ Championships.
John was inducted into the Basketball Hall of Fame in 2017 and the Maori Sports’ Hall of Fame in 2019.