Institute of Expert Witnesses

Providing specialist advice and support in accident cases

The Institute of Expert Witnesses offers professional impartial and independent advice and provides qualified expert opinions to support the legal process of resolving cases of accidents and injury.

William Duncan MacKay IFMGA, ISIA & FRGS

William Duncan MacKay IFMGA, ISIA & FRGS


William Duncan MacKay has more than 40 years experience advising, coaching, consulting and teaching in outdoor activities, physical education, recreation and sporting activities.

Williams is Chairman of the Institute of Expert Witnesses and as a former Army officer specialises in armed service cases having worked as an Army sports master at arms in the Royal Army Physical Training Corps.

He is an active International Federation of Mountain Guides Assocation (IMFGA) and International Ski Instructors Association (ISIA) guide and former president of the Association of British Mountain Guides BMG.

William currently advises the BMG on guiding matters and mountaineering and skiing accident investigation as well as acting as an advisor to a number of adventure holiday companies.

He also works as an independent worldwide consultant in a number of different areas of expertise, as an advisor for BS8848 with the British Standards Institute (BSI) and its corresponding ISO for competency of leaders and instructors in worldwide adventure sports and activities.

During the latter part of his military career, William worked as an accident investigator with the Land Accident Investigation Team (LAIT) and advised the Treasury as a subject matter expert.

He was also formally advisor and tutor to a number of sporting governing bodies, has competed at national and international levels and holds a number of national sporting qualifications.

William is a Law Society Checked expert witness who has successfully acted upon instructions from many solicitors and insurance companies in more than 200 cases and continues to advise in a number of different legal scenarios.

William's full CV can be found here

For more about William's areas of expertise and his work as an expert witness contact us on 0117 986 2194 or at

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