“[U]ndoubtedly there is a natural bias to do something serviceable for those who employ you and adequately remunerate you. It is very natural, and it is so effectual that we constantly see persons, instead of considering themselves witnesses, rather considering themselves as paid agents of the person who employs them.” (Abinger v Ashton (1873) 17 LR Eq 358 at 374)
The NSW Law Reform Commission in their 2005 Expert Witnesses Report identified several types of bias which can arise with respect to expert witnesses, undermining their impartiality and independence. These include adversarial bias (tailoring evidence to support one’s client), unconscious partisanship (a more subtle form of bias stemming from the situation of being employed by counsel and the incentive to provide evidence which support’s their employer’s cause) and selection bias (counsel choosing experts based on those whose view is known to support their case). Conflicts of interest may also arise due to long standing relationships with the parties involved in the proceedings or due to an employment relationship with the party that the expert is providing evidence for.
Similarly, Lord Woolf’s Access to Justice Reports (UK) highlighted the difficulty for expert witnesses to maintain independence and impartiality:
“Most of the problems with expert evidence arise because the expert is initially recruited as part of the team which investigates and advances a party’s contentions and then has to change roles and seek to provide the independent expert evidence which the court is entitled to expect”
As a result of bias which can arise when expert witness’ are utilised, the UCPR code of conduct (Schedule 3) for expert witnesses emphasises the expert witness’s overriding duty to assist the court, the need for expert witnesses to be impartial and independent and mandates that expert witnesses acknowledge that they have read the code and agree to be bound by it.
The importance of compliance with this Code was highlighted in Investmentsource v Knox Street Apartments  NSWSC 1128 where McDougall J noted that the intention behind the amendments to the former Schedule 3 Code of Conduct (found in Sch K to the Supreme Court Rules) was to emphasise that, as a general rule, expert evidence should not be admitted unless the expert, at the relevant time, had committed to the obligations in the Code of Conduct. Expert witnesses must have a conscious appreciation of the Code of Conduct requirements at the time of preparing their report which is to be used as evidence.
In the UK, the case of National Justice Compania Naviera SA v Prudential Assurance Company Limited  2 Lloyd’s Rep 68 (The “Ikarian Reefer”) clarified the UK position regarding the general duties of expert witnesses noting that expert evidence presented to the court should be the independent product of the expert uninfluenced by the pressures of the litigation in question and that an expert should state the facts or assumptions upon which their opinion is based and should not omit material facts which could detract from their concluded opinion.
Importantly, the practical disadvantages of failing to ensure expert witnesses are independent were highlighted in Anglo Group Plc v Winther Brown  EWHC Technology 127:
“It needs to be recognised that a failure to take … an independent approach is not in the interest of the clients who retain the expert, since an expert taking a partisan approach, resulting in a failure to resolve before trial or at trial issues on which experts should agree, inflates the costs of resolving the dispute and may prevent the parties from resolving their disputes long before trial.”
Where an expert has an interest in the case, for example when acting on a contingent fee basis or where they are an employee of the party they are appearing for, UK authority suggests that the court should be aware of this fact as soon as possible and that the question of whether the expert should be permitted to give evidence will be determined by weighing the alterative choices if the evidence is excluded (The Queen on the application of Factortame v Secretary of State for Transport (No 8)  3 WRL 1104. The Court however noted the undesirability of contingent fee agreements in the context of expert witnesses, holding that it would be a “very rare case” where such evidence obtained on the basis of such an arrangement would be permitted to be admitted.
The need to disclose any impediment to an expert witness’s independence has been highlighted in various UK decisions:
“Where an expert has a material or significant conflict of interest, the court is likely to decline to act on his evidence, or indeed to give permission for his evidence to be adduced. This means it is important that a party who wishes to call an expert with a potential conflict of interest should disclose details of that conflict at as early a stage in the proceedings as possible.” (Toth v Jarman  EWCA Civ 1028)
The court also rejected arguments that disclosure of conflicts of interests was not necessary unless there was a request to disclose, stressing that interests which were not obviously material should be disclosed by the expert to the party they were instructing and by that party to the other parties to the proceedings. It was held that it was for the court to determine whether a conflict of interest was material or not.
There are several consequences of a determination of lack of independence of an expert witness including:
- their evidence being declared unacceptable or if given, being disregarded once the impartiality has been uncovered;
- the court ordering costs against the expert witness (see, eg, Phillips v Symes (Abankrupt)  1 WLR 2043);
- being reported to their professional body for misconduct (see Pearce v Ove Arup Partnership Ltd & others  EWHC 481 for a UK example); or
- potentially being liable for a suit in negligence (See Jones v Kaney  AC 398).
Because of the strict judicial approach to the independence of experts and the codification of the requirement in the UCPR ExpertsDirect ensures that expert witnesses familiarise themselves with the duties they owe to the court and that they are aware of the associated procedural requirements.
This article was prepared in conjunction with Madeleine Vella.