John is now a consultant to the firm providing advice and assistance to its solicitors in the area of trusts, estates and general business law and, in particular trust and estate litigation.

In April 2006, when Conway Maccallum (of which John was then managing partner) merged with Diamond Peisah to form Diamond Conway Lawyers, John became a partner of Diamond Conway and significantly expanded the area of his practice in the general area of trusts and estates. His vast business law experience has been of great benefit to him and his clients in dealing with issues arising in trusts and estates and enabled him to bring a commercial perspective to bear upon the resolution of those disputes.  

In 1994, John was accredited by the Law Society of New South Wales as a specialist in Business Law. In 1995, John was also accredited by the Law Society of New South Wales as a specialist in Wills and Estates Law.  

He has been a member of the Law Society Specialist Accreditation Advisory Committee (Wills and Estates) which sets assignments and examinations for solicitors seeking specialist accreditation in wills and estates and then marks them. He has also been an assessor to whom appeals from decisions of the Advisory Committee have been referred for determination by the Committee.  

John has frequently delivered papers and chaired seminars for professional education bodies, such as the Law Society, the College of Law and the University of New South Wales in the area of trusts and estates.  

He has a reputation within the profession and elsewhere as a leading expert in the area of trusts and estates.  

Since 2017 John has been included in Doyles Guide as a leading/recommended Wills, Estates and Succession Litigation and Planning solicitor.