While class actions are an established part of the Australian legal system, the last 5 years have seen a marked increase in class action litigation, a fact partially attributable to the US financial crisis in 2007. Australia is now the second most likely jurisdiction after the USA where a corporation will face class action litigation.
A class action in Australia requires seven or more claimants with claims against the same defendant with similar or related circumstances. These claims must give rise to a substantial common issue of law or fact. A significant aspect of class action litigation is a strong reliance on expert evidence. Here are our top three tips for briefing an expert witness in a class action:
1. Make sure they have an independent voice
The Federal Court’s practice direction on expert evidence lists the first and overriding duty of an expert is to the court rather than the appointing party. The expert is not merely an “advocate” for his or her party. Parties should be careful when briefing an expert not to compromise their independent role. In particular, a party should notify an expert of their duty to the court and provide the expert with a statement of the ethical duties of an independent expert. Parties should be aware that a failure to provide an expert with the Expert Witness Code of Conduct could mean their evidence is ruled inadmissible. To maintain the independence of an expert, lawyers should:
a) Avoid direct contact between the client and the expert
b) Maintain records of communication between lawyers and experts
c) Ensure language reflects the desired objectivity of the expert.
2. Utilise shadow experts where necessary
There are times when an area of expertise is beyond the knowledge of the parties and their lawyers. At these times parties may hire a consulting expert known as a shadow expert. Shadow experts are party appointed experts who review the work of another expert. These experts can also assist lawyers in understanding technical issues as well as identifying specific questions for the independent expert. Such experts have no overriding duty to the court and as such no need to maintain an objective voice. While there is no barrier to a consulting or shadow expert later giving evidence in court, practitioners should advise experts to be open about this shift in role within their report rather than allowing it to arise in cross examination.
3. Ensure evidence is timely
Parties should be aware that courts enforce a strict schedule. Experts should be retained at an appropriate time to ensure they have scope to understand the matter but also sufficient time to produce a report. If parties are unable to meet the court’s schedule they run the risk of excluding their own evidence. To this end, parties should take care to choose experts who are reliable and have experience with the demands of the judicial system.
4. Make sure there is a basis for their opinion
It is necessary that parties recall that the facts and opinions underlying the expert evidence must be able to be proven. Experts are in a unique position of providing opinion evidence. However, such evidence must be based on facts that are disclosed to the court so they are able to asses how the opinion was reached. A failure to do so could mean the court will reject the evidence.
5. Take a backseat role in finalising a report
It can be difficult to balance the need to ensure an expert’s report is in an admissible form and overstepping the limits of influence on an experts opinion. While commentary suggests there is no ethical reason why a lawyer cannot comment on the final form of a report, lawyers should avoid ‘legal rewriting’ or commenting on opinions on substantive questions. The easiest way to avoid this issue is to provide a detailed brief from the outset to outline expectations on structure.
While the above tips are useful for anyone engaging an expert they are particularly important in class actions. Class actions are heavily reliant on expert evidence due to a wide breadth and complexity of issues. This may also mean parties engage a number of experts rather than one or two. To this end, parties should keep in mind the above tips and ensure expectations are set as early as possible to ensure the admissibility of their expert evidence.
This article was prepared in conjunction with Susan Flynn.
 Allens Linklaters, ‘Class actions in Australia’ (Publication, August 2014) 1.
 Ibid 1.
 Allens (2003) ‘Understanding expert evidence: Litigants and their advisors need to understand the fundamental principles of expert evidence’ Focus: Commercial Litigation.
 Federal Court of Australia, Practice Note CM7 – ‘Expert Witnesses in Proceedings in the Federal Court of Australia’.
 Albert Monichino ‘Aspects of Expert Evidence: Briefing of Experts and Finalising the Report’ (Paper presented to the IAMA “Expert Evidence Fundamentals: Tips and Traps” Seminar, 8 October 2012), 14.
 Commonwealth Development Bank of Australia Pty Ltd v Cassegrain  NSWSC 980
 Monichino, above n 5, 19.