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Expert witnesses: independence and experience

  • United Kingdom
  • Real estate sector


Expert witnesses often play a very important role in dispute resolution. Their opinion on an issue may be the most important part of a case. It is therefore vital for parties to a dispute to choose their expert witness wisely. 

The recent decision in Proton Energy Group SA v Orlen Lietuva [2013] All ER (D) 206 highlights the need for expert witnesses to have more than a general knowledge of the discipline in which they are giving evidence and not be too closely connected with their instructing party. The case concerned expert witnesses giving evidence before the court but the comments of HHJ Mackie (QC) apply to expert witnesses in all forms of dispute resolution.

The dispute in Proton concerned whether dealings between the two parties had given rise to a contract for the sale and shipment of crude oil. At the hearing of an application for summary judgment, the Deputy Judge concluded that the issue of whether a contract had been entered required a trial so that evidence was available from those involved in the transactions.

Orlen’s expert was said to be:

“a good witness in that he was honest, highly qualified in the oil industry in general and detached and straightforward in his answers”.

However, his experience was as consultant to the oil and gas industry, advising on strategic corporate decisions and acquisitions of oil field properties. He had never worked for a trading company. The evidence he gave was hypothetical, based upon what he thought traders at Conoco (the company of which he had the most experience) would have seen. HHJ Mackie (QC) said his principles were a set of impressions, not based on firm evidence or solid experience, which he then applied to the facts of this case to reach conclusions. His evidence was of little assistance to the court and what he had to say of any relevance was within the experience of most commercial judges.

Proton’s expert was also said to be:

“straightforward and honest but also forthright”.

However, in cross examination it came to light that he had known the partner in Proton’s firm of solicitors dealing with the case for 18 years. For 12 years, the partner had been involved in commercial conferences and seminars which the expert’s company had put on for profit. In addition, the connection between the partner and the expert was referenced on each of their websites. HHJ Mackie (QC) said this was not the worst of failures to disclose an interest he had come across but:

“this connection, which included money, was a closer one than usual and should have led [the firm of solicitors] to choose another expert or at least make full disclosure of the link”. 

Although HHJ Mackie (QC) in this case drew no relevant conclusions from the expert evidence, he said that the opinions of Proton’s expert were more consistent with logic and the experience of the court, despite the limits on his independence.

An expert who does not have recent experience in his subject area may also be subject to lengthy cross examination by opposing counsel. This was highlighted in one of a series of judgments in the high profile litigation of Humber Oil Terminals Trustee Ltd (“HOTT”) v Associated British Ports (“ABP”)1. In an application made by ABP for the payment of an interim rent ([2012] EWHC 1336 (Ch)), Sales J had to consider expert evidence on the calculation and payment of ships and cargo dues as part of the valuation exercise. Mike Garratt gave evidence for ABP and Dr Sidney Gilman gave evidence for HOTT (a joint venture between 2 oil companies - Conoco and Total). Both experts had 30 years experience in the ports and shipping industry but in cross examination it became clear that, since 1992 Dr Gilman had operated as an independent consultant with limited engagement in advisory work relevant to fixing ships dues.  Sales J concluded that:

“Mr Garratt had the more detailed and up-to-date experience of market usage in relation to the setting of ship and goods dues, I also found his evidence better reflecting Government policy than that of [Dr] Gilman and was generally more persuasive. Accordingly, where their evidence conflicted, I prefer the evidence of Mr Garratt. I found the evidence of Mr Garratt to be thorough, balanced and carefully reasoned, and I accept it in substance in its entirety.”

Surveyors need appropriate qualifications and experience

So, what points can be taken from these decisions? It is critical for an expert witness to have the skills and knowledge to be able to opine on the issue in dispute. In a property context, surveyors are often asked to provide expert evidence in a variety of disputes including lease renewals, rent reviews and dilapidations. It is important that the surveyor has appropriate qualifications and experience.  It is very common for an expert to be cross-examined by opposing counsel on his skills and experience in an attempt to discredit him by exposing his lack of knowledge. As was the case in Proton and ABP, it became clear to the court in cross examination, that one expert did not have the requisite knowledge to be able to give direct evidence on the relevant issue. 

Before instructing an expert, solicitors should ensure they have the necessary qualifications, experience and knowledge appropriate to the issue. The expert should be able to provide a detailed CV and references and these should be checked carefully and tested.

It is also important for an expert witness to give an objective unbiased opinion. His overriding duty is to the court or tribunal in which the dispute is heard. He therefore needs to provide his independent assistance to the court or tribunal in relation to the matters within his expertise. This duty overrides any obligation to the party from whom the expert has received his instructions or by whom he is paid. If the expert has a clear connection with his instructing party, then he may be accused of lacking independence.

The importance of disclosing any potential conflict of interest on the part of experts was emphasised in Proton but also by the Court of Appeal in the earlier case of Toth v Jarman [2006] EWCA Civ 1028. The Court of Appeal in Toth held that a conflict of interest did not necessarily disqualify an expert witness. The key question was whether the expert’s opinion was independent. However, it stated:

“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..” 

In the property world, surveyors and solicitors will often work together to promote their services which will include joint seminars and conferences for the benefit of their clients. They will often socialise at events and attend lunches to develop their business. Where there is a close connection, solicitors should give careful consideration to whether the expert may be perceived to lack independence. It may be appropriate to instruct a different expert at the outset or make full disclosure of the connection at an early stage of the relevant proceedings to ensure their evidence is not criticised at trial.

1Lisa Jamieson and William Densham of Eversheds LLP acted on behalf of Associated British Ports in this litigation.