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John McGuiness

John McGuiness
Level 12
20 Martin Place
NSW 2000
+61 2 9338 2613


Who's Who Legal Arbitration: Expert Witnesses

John is a leading dispute advisory expert and has many years’ experience in advising clients and providing objective analysis of transactions in major commercial disputes.

He draws on skills from accounting, finance, costing and general commercial advice to deliver analysis and opinions on issues that generally involve large data sets or complex issues. A significant part of John’s work involves the provision of valuation advice related to assets, equities and other matters in dispute settings. He has delivered many valuation reports across a wide range of industry settings.

John provides expert evidence in commercial matters where there are significant differences (or disagreements) of financial outcomes. This role requires the preparation of simple yet comprehensive reports and financial models to assist the court or arbitration.

He is recognised as a leading commercial arbitration expert witness in the 2016 and 2017 editions of Who’s Who Legal: Arbitration.

He is also recognised in the 2016 editions of Who’s Who Legal: Forensics and Litigation Consulting 2016 and Who’s Who Legal: Economic Consulting – Quantum of Damages.

His work is acknowledged for its objective nature and conceptual merit, for example: “ [the court] accept[s] that in giving his evidence, Mr McGuiness was a true professional witness” and “Mr McGuiness’ explanation of the application of a discounted cashflow methodology … was convincing.”

Another matter observed “Overall, in relation to matters of expert judgement and objectivity, I preferred the evidence of Mr McGuiness. His approach was particularly careful and thorough. He gave careful and reasoned consideration to his task at all stages of his engagement, from his initial report through to his evidence at hearing.”

He has experience with the preparation of joint reports with other experts which often extends to concurrent evidence or “hot tubs”. One matter noted “the mutual professional respect between [the other expert] and Mr McGuiness in the course of their joint expert evidence was clear.”

Also, “the experts [other expert and Mr McGuiness] to be called by either side were required to confer in advance of the hearing, and identify those matters upon which they agree, those on which they disagree, and their reasons for disagreement. This case is an excellent example of the value of that process … [it] helped to elucidate the evidence much more than would have resulted from the traditional adversarial approach.”

John also uses the expert witness experience in a pro-active way by advising major corporate and government bodies as they enter long-term agreements. The experience of resolving completion accounting, earn out mechanisms and other dispute related provisions is used to develop language in agreements which is reconciled with the intentions of the parties and is clear in its operation. The parties have some clarity of expectations if a dispute under the agreement is referred for resolution.

John’s role as expert often involves the application of costing and pricing principles to establish estimates of the performance of a business but for a complaint. He schedules work efforts from the gathering of information, financial modelling, costing methods, statistical analysis and delivery of reports with an objective of simplifying concepts for readers that are not subject matter experts.

John regularly draws on data analytics and electronic discovery solutions which enable teams to access large volumes or disperse sets of data. He integrates, analyses and presents data using statistical or other techniques to facilitate a deeper understanding of the issues relevant to a matter.

John’s industry experience covers government, financial services, energy and natural resources, industrial markets, property and construction, infrastructure and telecommunications.

WWL says: John McGuiness is well respected as an accountancy expert witness and regularly assists arbitrations with asset valuation matters involving a number of industries.

This biography is an extract from Who's Who Legal: Arbitration which can be purchased from our Shop.

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Nominees have been selected based upon comprehensive, independent survey work with both general counsel and private practice lawyers worldwide. Only specialists who have met independent international research criteria are listed.

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87 Lancaster Road, London
W11 1QQ, UK