Jonathan Humphrey


Suite 1001, Level 10, 309 Kent Street
NSW 2000, Sydney, Australia
Tel: +61 2 9255 9100


Peers and clients say:

"Mr Humphrey is reliable both in terms of deadlines and content"
"He is extremely diligent"
"You can feel at ease when working with Jonathan"


Jonathan leads HKA’s forensic accounting and commercial damages practice in Oceania and Asia. He is a chartered accountant with 25 years of experience advising clients as an accounting and finance expert on complex contentious matters. Jonathan specialises in the assessment of damages in commercial and investor-state disputes, including the quantification of lost profits and business valuations, with an established international background having worked on disputes related to all continents, and experience covering most industry sectors.

What do clients look for in an effective testifying expert?

Credibility. An “expert” has to been seen as exactly that, if one is not credible then a tribunal will not accept their evidence. Credibility comes from a mix of qualifications, experience and gravitas.

Experience and gravitas do not necessarily need to come from repeated testimony. At HKA, we have many experts with deep industry knowledge, who may have only testified a couple of times, or not at all. However, they are the best people in their areas as they know the issues inside out.

How has your membership of the Institute of Chartered Accountants enhanced your practice?

Qualifications are extremely important, no matter what your field of expertise, as they support ones’ credibility as an expert.

Much of my work involves the assessment of damages, which requires the analysis of historic financial records, the assessment of forecasts and the modelling of counterfactual scenarios.

The training and work experience I received while qualifying as a chartered accountant gave a great foundation in understanding financial records and the operations of a business. I draw on this knowledge every day in my work.

How do you effectively prepare for cross-examination when acting as an expert witness?

The key is to be overprepared. I go through my reports and identify those areas where I consider I will be cross-examined, so I am ready to explain to the tribunal the justification for my approach. However, there will always be some left field questions which you can’t anticipate, so you need to be ready to address those.

After the conclusion of a cross-examination, I often feel that I was too overprepared, but I’d certainly prefer it to be that way than the alternative.

What advantages accompany introducing experts early in the disputes process?

The early introduction of an expert helps in setting a client’s expectations. Often, the client’s view of their damages is different to their actual loss. By explaining the damages approach to a client early, this can often lead to a negotiated settlement, saving much time and cost.

In many instances, the damages expert is brought onboard after the submission of pleadings, which can often lead to a subsequent requirement to provide further and better particulars of the damages claim and an adjustment to the amount being claimed. Early involvement will mean that these additional pieces of work are negated and that time is available to do a proper analysis at the outset.

If you could change one thing about giving testimony as an arbitration expert, what would it be and why?

My main concern is always time, or rather the lack thereof. As a damages expert, my testimony is generally on the last day of the hearing. Oftentimes, the hearing is overrunning and the schedule is compressed, which eats into the time allocated to the expert evidence.

While it may seem strange to want to subject oneself to more time giving evidence, I feel that sometimes tribunals do not have sufficient time to hear the opposing positions of the experts and to get to the crux of the matters in disagreement.

What challenges do you face with the increased volume of data being used in disputes, and how are you navigating them?

The issue with an increased volume of data is that this invariably leads to increased time and costs. I am generally asked to undertake one of three approaches, either to review all the documents; provide a list of key words which the legal team then use to search the disclosure database; or I am briefed with the documents which the legal team consider relevant to my instructions. There are advantages and disadvantages to each approach.

I do find that, sometimes, the disclosure exercise can be part of a game between the parties, so a proportionate approach has to be taken to the review of some of the information.

What has been your proudest achievement to date?

The first time I gave evidence was in an arbitration in Madrid; it went very well with the tribunal finding in favour of my client and agreeing with my damages calculation.

About two years later, the chairman of that tribunal appointed me to act as the independent expert for his client. To have such validation as a junior expert was fantastic, I interpreted it to be confirmation that I couldn’t have messed up too badly.

What is the best piece of advice you have ever received?

This was received from my late mentor and colleague David Saunders. His advice was to make sure you engage with the tribunal, addressing all answers to them as they are the audience. He also told me to always be honest, as we are our reputation, and to not take things personally, after all it is the job of the cross-examiner to try and discredit your opinions.