Expert evidence in Australia: A more transparent path post-Dasreef

In 2011 the High Court of Australia handed down what has become a seminal decision in Australia on the admissibility of expert evidence in Dasreef Pty Ltd v Hawchar (2011) 243 CLR 488.  The case has had significant impact and been applied extensively.  The paramount concern of the Australian courts post-Dasreef has been to focus rigorously on the criteria for admissibility in s 79 and their forensic application, as emphasised by both the plurality decision and the minority decision of Heydon J.  The plurality emphasised, at [32], that to be admissible under section 79(1):

“the evidence that is tendered must satisfy two criteria.  The first is that the witness who gives the evidence ‘has specialised knowledge based on the person’s training, study or experience’; the second is that the opinion expressed in evidence by the witness ‘is wholly or substantially based on that knowledge’.”

Even so, the criticism of expert evidence is often strident.  Justice Heydon observed, at [90] that:

“Opinion evidence is a bridge between data in the form of primary evidence and a conclusion which cannot be reached without the application of expertise.  The bridge cannot stand if the primary evidence end of it does not exist.  The expert opinion is then only a misleading jumble, uselessly cluttering up the evidentiary scene.”

The numerous Australian cases post-Dasreef in diverse jurisdictions demonstrate an exacting approach to s 79 criteria and also an expectation, and requirement, by the courts that experts will provide a transparent pathway for their reasoning:

• Wilson, “Expert Evidence in Australia: A more transparent path post-Dasreef”” (2014) 33 Civil Justice Quarterly 412.
• Wilson, “Expert Evidence in the Digital Age in Australia”, (2012) Civil Justice Quarterly 216.