Glen is a Professional fulltime Referee for New Zealand Rugby Union. He returned to New Zealand to take up the whistle as the next phase of his professional rugby career
He has played for Bay of Plenty, Chiefs, New Zealand Maori, New Zealand Barbarians and, after moving to the UK in 2004, for the London-based Saracens in the UK’s Guinness Premiership. He was the club’s leading points scorer of all time in the Premiership and after the 2006/07 season when he was named the Professional Rugby Players’ Association Player of the Year for his 428 points in all competitions.
In that same season, Glen won the Saracens Player of the Year Award and was the Gilbert Golden Boot winner as the Premiership's top points scorer and goal kicker.
Glen started refereeing age grade rugby in Tauranga while playing for the Chiefs, and he continued to develop his skills in the United Kingdom where he is currently contracted to play with Saracens. Jackson first picked up a whistle seven years ago, and since then has refereed club rugby in New Zealand and in the UK. He has completed his English RFU referee exams and is a member of the Hetfordshire Referees Society.