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\ ˈek-ˌspərt — expert

Having, involving, or displaying special skill or knowledge derived from training or experience.
\ ˈˈe-və-dən(t)s — evidence

Information drawn from personal testimony used to establish facts in a legal investigation or admissable as tesimony in a law court.

From Latin evidentia, ‘obvious to the eye’.

Duty of an expert

The overriding duty of the expert witness is to provide expert evidence to the Court. Not to act as an advocate to a party in the proceedings and not to mislead the Court. Unbiased opinions must be presented, even if they cause harm to the client’s case.

The purpose of the use of expert evidence is to provide the Court an objective and impartial assessment of key issues based on specialised knowledge. The specialised knowlede is generally based on training, study or experience.

Federal Court Expert Evidence practice Note

Expert evidence consists of fact and opinion. Data from an accounting system and the production of a sales ledger are facts. Facts, however, are not established until the trial. The valuation of a business and the quantum of damages are opinions.

Appointment of an expert

The expert may be appointed by a party and instructed to prepare an expert evidence report for the Court. If the party on the other side appoints an expert then a meeting of experts may be arranged. In the meeting of experts, the experts will discuss points of agreement and disagreement. A joint experts’ statement will then be produced highlighting these issues.

Alternatively. a single joint expert may be selected by both parties and whose appointment is approved by the Court.

Instructions to an expert

An instruction letter needs to clearly set out and include:

  • All the parties to the matter
  • The assumed facts
  • The requirements of the expert
  • The documents to be considered
  • Any relevant dates
  • Applicable codes

Consultation may be required with the expert prior to issuing an instruction letter, to clarify issues such as

  • the relevant questions that need asking and answering
  • the documents available and required to be discovered
  • any limitations of the expert

Role of an expert

The expert has two key roles:

  1. Explain the arguments and opinions clearly, so that they can be understood by the Court
  2. Present opinions that are logical and supported by acceptable facts and figures

Essentially expert evidence must:

  • identify the observed facts
  • identify assumed facts
  • establish there is a proper foundation for the facts upon which the opinions are based
  • clearly set out a reasoned approach
  • not omit material facts that could detract from the considered opinion

In summary, important factors relating to expert evidence include (1):

  • The expert is only to express opinions that fall within their field of expertise and or knowledge
  • The expert can not provide evidence that is nothing more than common knowledge
  • The expert job is to facilitative. It is not to take over the decisionmaker’s function.
  • The expert opinions are only as good as the facts upon which the opinions are based. If the facts can not be established then the opinions fall away.

Rules for experts

The expert evidence rules require the following information to be included in an expert’s report:

  • experts qualifications and experience
  • literature used in the report
  • facts, matters and assumptions on which the opinions are based
  • statement of the questions the expert was asked
  • reasons for the opinion expressed
  • if applicable, that a question falls outside the expert’s area of expertise
  • examinations, tests and investigations carried out
  • if an expert changes their views, those details must be included

Expert evidence rules to be followed include:

Admissibility of expert evidence

All expert evidence opinions must be based on facts. The facts could be (2):

  • results of tests carried out by the expert
  • facts observed by the expert
  • facts observed by another expert
  • facts observed by a non-expert witness
  • facts of general application based on the expert’s specialised knowledge

Both the facts upon which the opinions are based and the opinions can be disputed. Critical questions that can be asked of an expert and the expert evidence include (2):

  • How credible is the expert?
  • Is the expert an expert in the field?
  • Is the expert personally reliable?
  • Is the expert consistent?
  • Is the expert’s assertion based on evidence?

The conditions for the admissibility of expert evidence are summarised as follows (3):

  1. Demonstrate a field of specialised knowledge
  2. Identify an aspect of that field which the expert has proven knowledge
  3. The expert’s opinion is substantially based on that knowledge
  4. The expert identifies the assumptions of primary facts
  5. The evidence is submitted that supports the primary facts
  6. The facts on which the opinion are based form a proper foundation for the opinion
  7. The opinion requires demonstration of the scientific or intellectual basis of the conclusion


In summary, expert evidence must be based on the expert’s proven knowledge. The expert must be unbiased, credible, reliable and consistent. Opinions must be based on facts. Most importantly the expert’s duty is to the court.

  1. Hon M, Kirby (2011) Forensic Accounting — new rules and opportunities, Chartered Accountants Business Valuation conference
  2. A, Palmer, (2010) Proof: How to analyse evidence in preparation for trial, Thomason Reuters, 2nd edition
  3. Hon J D, Heydon (2018) Expert opinion evidence

Simon is a CA Accredited Business Valuation expert, Chartered Accountant and a Certified Fraud Examiner. Simon specialises in providing forensic accounting and valuation services. Prior to founding Lotus Amity, he was a Forensic Accounting partner with BDO Australia and led their National Forensics practice. He has worked as a forensic director for a major offshore forensic accounting practice which included assisting in multi-billion-dollar litigation in relation to the giant Bernie Madoff Ponzi scheme. Simon provides valuation services in disputes, for raising finance, for restructuring, transactions and for tax purposes.


Simon specialises in valuing private businesses and quantifying damages. He is a Chartered Accountant Business Valuation Specialist and Forensic Accounting Specialist with Chartered Accountants Australia and New Zealand (CA ANZ). He chairs the CA ANZ Business Valuation group for Queensland and is a member of the CA ANZ Trans-Tasman Business Valuation Committee.

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