Q&A: Expert evidence, then and now …

By Janet McKelvey, Holly Stephanos, Zelie Heger and Kate Lindeman
26 Nov 2020
Four barristers give their insights into how the role of the expert has changed, and what makes a good expert.

Question 1: What changes have you seen recently in the way experts have been providing evidence?

Janet McKelvey:I have been really surprised by how seamlessly the move to online hearings has been for most expert witnesses. In my experience, the online format has changed the way the evidence is given in that the experts tend to appear more relaxed when giving evidence. This is largely because the expert will be in a familiar space (such as their home or office) or in an office within a law firm. The effect on a witness of the design of a court room, which can be a little intimidating, has diminished. Also, the expert is able to better organise their materials in advance of giving evidence so there is less shuffling of papers than there is when in the confined space of the witness box. I have also found that the giving of concurrent evidence has been a much more polite affair. It is simply not possible for more than one person to speak at a time in an online hearing. Therefore, experts wait until the end of a question before answering. They also wait until their counterpart has finished speaking before they begin. This has led to the process being generally more orderly. I have had feedback from some witnesses that they prefer the online hearing format.

Zelie Heger: Courts are referring questions out to referees for inquiry and report with increasing regularity. The referee will have been appointed because of their expertise on the topic, but can then take evidence from other experts without being bound by the rules of evidence. A recent notable example is the appointment of a toxicology expert as referee in the PFAS litigation. While there is occasionally reluctance to what some perceive as a delegation of the judicial role, when used appropriately the referral procedure can be a way of minimising cost and delay.

Holly Stephanos: The key change in the way experts have been providing evidence recently, which arises as a consequence of COVID, is that it is far more common for experts to be giving evidence remotely by way of either videolink or phone. This requires a lot of forward thought by both the parties and the experts to ensure that the experts have, for example:

  • set up and tested their visual and audio equipment before the time of their evidence, so they are not delaying the progress of the hearing while fixing any technical issues;
  • downloaded or printed all of the key documents that they may require for their evidence, before their evidence starts; and
  • the ability to receive electronic copies of documents that may be emailed to them during cross examination – just because the expert is giving evidence remotely does not mean they can avoid the element of surprise during cross examination, when a party wants to put a new document to them.

Kate Lindeman: In largescale litigation, I have recently observed a shift towards the appointment of facilitators to assist experts in preparing joint reports. Such facilitators are often former judges or senior barristers, and the parameters of their role are usually outlined in orders made by the Court. In my view, this is a welcome development. A well-written joint report that narrows the issues in a dispute is of great assistance to parties and the Court, and if a facilitator is able to assist the experts in producing such a report, the facilitator’s appointment seems likely to ultimately produce cost savings through reduced time being devoted to expert evidence at trial, and a reduced need to consult experts’ earlier reports.

Janet McKelvey specialises in planning, environmental, valuation and compulsory acquisition law. She regularly appears in all classes of the Land and Environment Court and the NSW Court of Appeal for local councils, NSW State agencies and developers.

Holly Stephanos is a barrister specialising in planning and Land and Environment Court matters, regularly appearing in merits appeals, enforcement proceedings and prosecutions, declaratory proceedings, and land acquisition and compensation disputes.

Zelie Heger practises in public and commercial law. She is currently acting for Commonwealth and State governments and private entities in a range of constitutional, administrative and planning law matters and tort and contract disputes.

Kate Lindeman has a wide-ranging commercial law and public law practice. In commercial law, she is experienced in matters ranging from large-scale class actions and significant appeals through to small first-instance matters. Her public law practice includes constitutional law, administrative law and statutory construction, and she regularly appears in planning and professional disciplinary matters.

Question 2: What makes a "good" expert? Can you provide some examples?

Janet McKelvey: A good expert witness is confident in their opinion but also has done the work in terms of research to support and explain their opinion. The best expert witnesses are across the detail of their own evidence as well as their counterpart’s. The ability to immediately recall where something has been said and to understand how all of the elements of the evidence of a case fit together is an especially valuable skill. I also find the ability to communicate complex or technical evidence in a plain English way is a rare but useful attribute of an expert witness. No matter how skilled and experienced a witness may be, if their point cannot be fully understood by the decision maker, their evidence will be wasted.

Zelie Heger: A good expert is across the details of their brief; identifies the assumptions on which their opinion is based; asks for clarification and further information if needed; makes necessary and appropriate concessions; and is willing to acknowledge when an issue is outside their area of expertise.

Holly Stephanos: A good expert is one who is:

  • thorough – they are familiar with all of the material in the proceeding relating to their expertise area and ensure that they properly understand the issues in dispute that are relevant to them;
  • able to effectively communicate and provide well-reasoned opinions – the Court cannot simply accept a bald assertion, even from the most qualified of experts. The expert must be able to clearly identify the process of reasoning that they followed to reach their conclusions and explain why they hold a particular opinion, which is a critical skill that is sometimes lacking; and
  • able to consider the issues relevant to their area of expertise in a balanced and impartial way, rather than simply attempting to “advocate” for their client’s position – during cross examination, the most impressive expert witnesses are those that are able to make reasonable concessions where appropriate. This doesn’t mean they should concede their position, but aggressively maintaining an opinion that has been demonstrated to be unreasonable can undermine the value of all of the evidence otherwise given by that expert.

Kate Lindeman: In my opinion, a “good” expert is able to articulate their views clearly and succinctly, takes care to avoid moving beyond their expertise, and is able to identify when to make appropriate concessions, and when to maintain their position. An expert who produces a well written report but then is unable to explain their opinions in a clear and compelling manner when giving oral evidence quickly loses credibility. The same is true of an expert who is unwilling to make appropriate concessions under cross-examination, as such experts often appear to be advocates for their client’s position, rather than an impartial expert aiming to assist the Court.

Question 3: What are some mistakes that experts make? How can they be avoided?

Janet McKelvey: I find the most costly mistake an expert can make when giving evidence is not conceding on an issue when a concession is appropriate. If an additional fact or circumstance would change an expert’s opinion, they should say so. A proper concession does not necessarily undermine the witness’s evidence – rather it can give comfort to the decision maker that an independent view is being expressed and that the witness can be generally trusted. On the other hand, a dogged adherence to a particular opinion, even in the face of overwhelming contrary evidence, has the effect of undermining the whole of the expert’s evidence. It demonstrates that the expert does not understand their role as an expert witness (especially their obligations under the Expert Witness Code of Conduct) and may lead to adverse comments about the expert in a judgment, which can be personally and professionally devastating.

It is worth noting that an expert witness, while independent, still forms part of one party’s team. The expert can seek guidance from the lawyers about their obligations and they should certainly consider any feedback given by the lawyers in the team in terms of the style of their written evidence. If the lawyers in the team cannot understand a report, chances are the decision maker will also have difficulty!

Zelie Heger: Never assume the reader has background knowledge in your area of expertise. It is best to explain everything – even the most basic concepts – and to do so in language that a non-expert will understand.

Holly Stephanos: Two things spring to mind. The first is when experts fail to fully explain all sides of an issue to their legal team. An expert may have formed an opinion about a matter, but the legal team will be best assisted if the expert can also explain to them the key assumptions they have made, whether the opinion might change if the assumptions are wrong, and any other weaknesses that the team ought to be forewarned about. These matters should be raised early so that the opinions can be properly tested before their client advances (at a great expense) too far into the litigation.

The second mistake occurs during cross examination, when an expert tries to guess where the cross examiner is taking them and mould their answers accordingly. An expert should simply answer honestly based on their expert views, without second guessing how their answers might be used.

Kate Lindeman: Examples of common mistakes made by experts include over-reaching as to their expertise, being overly reliant on assistants in preparing to give evidence and slipping into the role of an advocate. Expert evidence should be prepared with the end goal in mind – the expert giving compelling evidence in the witness box, likely in the context of a hot tub. In my view, if that end goal borne in mind, the expert will be less likely to over-reach as to their expertise, as this will be readily apparent when they come to give evidence. Similarly, over-reliance on assistants may be avoided if the expert keeps in mind that it will ultimately be them personally giving evidence before the Court. Finally, an expert may be less minded to act as an advocate if they are mindful of the fact that their views will need to be defended in a witness box in front of their peers.

Question 4: Do you have any tips for effectively presenting expert evidence remotely (eg. by videolink)?

Janet McKelvey: Be organised! Make sure any documents that might be needed are marked or already open on screen so that there are no delays while documents are found or opened electronically. An expert should know where everything they may need is. Also, notwithstanding that the evidence may be being given from home, rules of Court attire should be observed so it is best to dress in a suit. Other court room etiquette such as only drinking water from a glass (no drink bottles!) and not drinking tea or coffee while giving evidence should also be observed. It is also best to try to have a neutral/professional looking background so as to not distract the decision maker from the substance of the evidence.

It is also important to remember that the Court (and the other party’s counsel) will have a close up view of a witness’s face when evidence is being given virtually. Be conscious of, and avoid if possible, facial responses to a counterpart’s evidence – a roll of the eyes or a smirk will be able to be clearly seen!

Zelie Heger: Given the inevitable technical difficulties involved in remote hearings, it is even more important than usual that cross-examiners and experts are clear and concise in their questions and answers. Pre-hearing conferences with the expert should be conducted using the platform the Court will be using, including any file sharing technology that will be used to display documents in Court.

Holly Stephanos: My top tips are listed in response to question 1. To that, I would add that an expert should also think about their surroundings and ensure that their background is appropriate. Also, as anyone attending meetings remotely will now appreciate, a quality set of headphones are invaluable to minimise audio feedback.

Kate Lindeman: In addition to providing experts with training in the software to be utilised in giving evidence remotely, I would recommend impressing upon experts that evidence given remotely must be treated with the same degree of formality as evidence given in person. Justice Ball’s recent observations in Blackmores Ltd v Jestins Enterprises Pty Ltd [2020] NSWSC 1177 at [98] are apposite in this context, and may be useful to pass on to experts:

"[The expert] as is usual these days, gave his evidence by videolink. He was wearing a sweatshirt. More significantly, when he was not giving evidence himself he appeared on occasions to be attending to text messages or emails on his mobile telephone. No doubt, as hearings by videolink have become standard practice in response to the pandemic a degree of informality has crept into the processes followed by the Court and it has become easier for witnesses to overlook the fact that they are still giving evidence in Court proceedings. Nonetheless, a degree of formality remains important. … [The expert’s] conduct was not what I would have expected of an expert witness; and there may be a question whether it is appropriate for him to charge for the time he spent giving evidence when he used some of that time to attend to other tasks as well.” 

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Clayton Utz communications are intended to provide commentary and general information. They should not be relied upon as legal advice. Formal legal advice should be sought in particular transactions or on matters of interest arising from this communication. Persons listed may not be admitted in all States and Territories.