During his time as a barrister Wyn concentrated, mainly, on civil work. He undertook large volumes of personal injury cases, planning cases and cases involving sports law. In the two years immediately before becoming a judge Wyn acted for the Home Office in cases related to international terrorism.
Wyn was the specialist Chancery Circuit Judge for Wales between April 2004 and January 2007. He was a High Court Judge between January 2007 and February 2017. He is currently President of Welsh Tribunals and a judge of the Courts of Appeal of Guernsey and Jersey.
Wyn has been involved with Welsh rugby over decades and since his retirement as a full time judge he has become a member of the judicial panels of the Premier League and the Football Association.
He is proud to be the President of Pendyrus Male Choir and Tylorstown RFC.