Experts have a paramount duty to furnish legal officers with scientific information to ensure the accuracy of their conclusions. This enables a Judge or other legal personnel to form an independent and unbiased view on proving factual issues in proceedings.

There are many cases where it is difficult to locate an appropriate expert to comment on a particular fact in issue. There are avenues adopted by the Courts to overcome this obstacle and this is a case where Lee J of the Federal Court of Australia has decided to consider the appointment of an assessor.

It is important to note that the nature of such an appointment must not usurp delegation of judicial powers.


In the matter of McNickle v Huntsman Chemical Company Australia Pty Ltd (Expert Evidence) [2021] FCA 370, the applicant claimed that products containing glyphosate were carcinogenic and consumption or inhalation of these organophosphorus compounds causes Non-Hodgkin’s Lymphoma. The applicant in this case alleged that a corporation trading as Monsanto negligently sold these products despite knowledge of its effects.

Appointment of a Court Assessor

Due to the seriousness of the allegations made by the applicant, the Court considered it prudent to appoint a Court assessor to assist with unravelling the issues within the matter and ensuring that bias in expert evidence is not a concerning factor.

Unsurprisingly, both the applicant as well as the respondent disputed such a suggestion and sought to rely upon their own experts notwithstanding the difficulties associated with locating an expert that can provide expert opinions on the specialised area.

The Federal Court relied upon section 33ZF of the Federal Court of Australia Act 1976 (Cth) (“Act”) in conferring its power to appoint a Court assessor. The Act confers a power to “the making of orders as to how an action should proceed in order to do justice”. Moreover, the Federal Court exercised its discretionary power to appoint a Court assessor.

In appointing an assessor, the Court considered the functions of the assessor and noted that they would not assess, but would rather act as an ‘assistant’ to the Court. The examples provided by the Court as to the functions of the Assessor were as follows, the Assessor would:

  1. assist the Court in explaining the expert reports;
  2. furnish materials for the Court to act upon and ensure all evidence is given proper consideration;
  3. deliver tutorials to the Judge on relevant specialised topics;
  4. help the Judge listen to and understand the technical evidence;
  5. submit questions to counsel or witnesses at the hearing and help the judge in understanding the factual issues in dispute;
  6. confer with the Judge after a hearing to ensure their understanding of the technical concepts discussed; and/or,
  7. review the draft judgment for technical accuracy.

Key Takeaways

This decision not only shows that the Courts are able to assist the parties in understanding complex expert evidence, but rather it shows that there are many avenues that can be taken, to ensure that sensitive and delicate matters can be free from expert bias which is often influenced by parties to proceedings and their representatives.

The appointment of assessors is possibly going to become a more common theme in the Courts system for more complex matters, however, special care ought to be taken to ensure that assessors only perform permissible functions and do not act as expert witnesses.

It is of utmost importance that experts, in writing their reports, take caution and ensure that a scientific position is broken down and simple to understand. Failure to do so may result in significant costs consequences and unfavourable decisions.