Colloquially known as hot-tubbing, the practice of concurrent evidence is gaining significant traction in Australian jurisdictions. In fact, the New South Wales Law Reform Commission hypothesised that perhaps ‘the taking of expert evidence concurrently will become the norm rather than the exception.’
By way of background, the process of concurrent evidence was described crucially by Chief Justice McClellan of the NSW Land and Environment Court in BGP Properties Pty Limited v Lake Macquarie City Council :
This involved the swearing in of the experts with similar expertise, who then gave evidence in relation to particular issues at the same time. Before giving evidence, the experts had completed the joint conferencing process, which enabled the court to identify the differences which remained and which required resolution through the oral evidence. Each witness was then given an opportunity to explain their position on an issue and provided with an opportunity to question the other witness or witnesses about their position. Questions were also asked by counsel for the parties. In effect, the evidence was given through a discussion in which all of the experts, the advocates and the Court participated.
What do experts need to know?
The concurrent evidence is seen as a way to overcome many of the issues with the lawyer-created adversarial system – and all the rigidities that come with it. As a non-lawyer, giving concurrent evidence will probably be much easier and familiar than giving evidence traditionally.
However, it is still important to remember that you are giving your opinion. You are not just trying to reach compromises with other experts to keep the judge happy. Try to make sure that you do not let your voice get drowned out, especially when you’re sharing the tub with as many as 5 other experts! This, of course, doesn’t just apply to in-court proceedings. In the joint-conference when narrowing down the issues, be sure to stand your ground and indicate where you differ from the other experts.
What do practitioners need to know?
Whilst counsel acknowledges the time-saving advantages to concurrent evidence, they often find it hard to accept losing ‘control’ of the evidence that comes before the court. Indeed, experts have given overwhelming support to this technique because they know that ‘there is less risk that their opinions will be distorted by the advocates’ skills.’
As any good practitioner knows, advocacy is not confined to the courtroom. The ‘loss of control’ in court makes a selection of experts and their preparation key. It is important to retain experts that will stand up for their opinions and will not be scared to point out the flaws in another expert. This might be based on their superior credentials and expertise in the area, or their previous courtroom experience, or even their personality. All of which can be found on their ExpertsDirect profile – except perhaps the latter! Further, proper explanation of the reason behind hot-tubbing, and the potential pitfalls that experts may fall into will optimise the way in which an expert performs.
This article was prepared in conjunction with Truman Biro.
  NSWLEC 399 (12 August 2004), .
 Walker Corporation Pty Limited v Sydney Harbour Foreshore Authority  NSWLEC 315 (9 July 2004).
 New South Wales Law Reform Commission, Expert Witnesses, Report No 109 (2005) [6.51].