'simply because someone has a great level of expertise in a particular subject, he or she does not necessarily have expertise in the art of being an expert witness'.

This article briefly examines the requirements for admissibility of expert evidence and the role of an expert. In doing so, we canvass areas where an expert might be challenged resulting in the expert 'coming undone' in the witness box. Finally, we touch upon the adverse impact that an expert's performance in the box might have upon an employer's reputation and raise some issues for consideration by employers.

Admissibility

Expert evidence is an exception to the rule against hearsay. Assuming the evidence is relevant, expert evidence must, to be admissible, relate to a field of specialised knowledge, be provided by a qualified person and be based (wholly or substantially) on that person's specialised knowledge.

One of the first assessments which is made when an expert report is served is whether or not the expert is truly an expert. If it appears that an expert is not in fact qualified in the particular field of specialised knowledge in relation to which he or she proffers an opinion, it is very likely that his or her expertise will be challenged.

This point is illustrated by a recent Federal Court case. A University lecturer gave expert evidence regarding, among other things, the condition of a truck purchased by the applicant. In assessing Dr M's 'expertise', the trial judge observed that he had not undertaken his own research or tests on heavy articulated vehicles save for an undergraduate thesis in 1974, nor had he conducted any tests or research on heavy vehicles or their design before 1998. He had not published in the area, had not supervised any doctoral students in the area and most, if not all, of his relevant research was undertaken by students without any actual testing of trucks. The judge also observed that there were important differences between Dr M's claimed expertise in his curriculum vitae when compared with the area of his research activities noted on the University's website. Her Honour concluded that Dr M's 'expertise' in the area of heavy vehicle dynamics and design, non-lineal vibrations, effects of whole body vibrations and bio mechanics was 'at best theoretical', and held his opinion to be inadmissible insofar as it went outside this theoretical domain. Dr M's error was not knowing the limits of his expertise and informing the court of those limits where appropriate.

The judge went on to hold that much of Dr M's 'expert opinion' was not relevantly based on the field of specialised knowledge and rejected parts of his evidence on this basis. Her Honour's comments about Dr M's evidence indicate the potential embarrassment for an expert and their employer institution where the institution's name is used. The judge said that it was 'generally impossible to be satisfied that his opinion was wholly or substantially so based. There are many instances in which it is apparent that his opinion was merely speculation', and that, as Dr M's report failed to differentiate between assumed facts or assumptions and his 'expert opinion', '[m]uch of his evidence was virtually incomprehensible, ill-ordered, illogical or manifestly erroneous.'

Expert's role

An expert's paramount duty is to the Court, not the party who engaged him/her. The reputational issues resulting from a lack of independence are illustrated by Lord Justice Leveson's address, which was reported to include the following comments:

'Not so long ago, experts might be well known for the line they would take and for always arguing the same evidence, even joining in with the 'obstructive tactics' of litigants.

One orthopaedic surgeon had the initials NWA – 'never work again' – because that was the evidence he always gave about the impact of an injury on a client.

He would always appear against another surgeon with the initials BTW – 'back to work' – because that was the contrasting evidence he would always give…'

Expert evidence is often rejected or its weight diminished when an expert assumes the role of an advocate for a party, or a prior relationship between the expert and the party retaining him/her is such as to cause a reasonable bystander to apprehend, or expect, a lack of impartiality in the expert's opinion. An expert is not precluded from accepting a retainer where he/she has, or had, a family, personal or business relationship with the party retaining him/her. However any prior or existing relationship must be disclosed so that the trial judge can make an assessment of the witness's independence and the effect of the relationship upon the expert's credibility.

Guidelines for expert witnesses

Most Australian courts have guidelines governing the role of expert witnesses which must be provided to an expert upon being retained. In Victoria, for example, the Supreme Court requires that a copy of the Expert Witness Code of Conduct be provided to an expert as soon as reasonably practicable after his or her engagement. The Code is a useful summary of the key requirements for expert witnesses, and addresses matters such as an expert's role and the limitations upon an expert's opinion that are to be set out in his/her report.

Issues for employers

An expert assumes an important role in our legal system. However, as the above discussion discloses, that role is not without risk. An expert may be criticised for his/her lack of independence or expertise, or for the manner in which a report is presented. The other party's lawyers are astute to the requirements of admissibility of expert evidence and look for every possible avenue to challenge an opponent's expert report. Cross-examination of experts can be ruthless. The process can result in judicial criticism of the expert in a judgment. This might necessarily give rise to concerns for employer institutions.

A preliminary issue for employers is whether or not the expert is acting within the scope of his/her employment in accepting instructions. Guidelines regarding outside appointments and the use of an employer's time and equipment pursuant to an appointment should be clear.

Experts often 'come undone' where they seek to give expert evidence outside their expertise, do not disclose a potential conflict, argue a party's case, or fail to properly set out assumptions made, tests undertaken, or materials upon which an opinion is based. It also occurs when they fail to submit their evidence to robust testing – 'the other side might well do it to [an expert] in public, and … the witness box can be very lonely in those circumstances.'

Employers might wish to review how they regulate expert engagements, if at all. Employers should consider whether it is worthwhile requiring academics to notify them when they are retained as an expert and providing some guidance (or checking that guidance will be provided) to academics about an expert's role and duties. While guidance is usually provided by the retaining party's solicitors, there is no guarantee that it will be, or that it will appropriately prepare your employee for cross-examination. Cross-examination can be harsh and employers have an interest in ensuring that the expert understands their role and is properly prepared given the potential adverse reputational consequences.