Experts in the firing line

9 minute read
18 August 2014

In complex construction and engineering cases, where the technical nature of the matters in dispute means that the court's decision will often largely depend on the credibility of each party's experts, choosing the right expert is essential.


Weatherford Global Products Limited v Hydropath Holdings Limited and Others concerned the manufacture and supply of a product known as the "Clearwell Product" by Hydropath to Weatherford. The Clearwell Product was an electronic box which was to be attached to oil pipes to prevent scale building up on the inside of the pipes. Due to concerns over the safety of the Clearwell Product, Weatherford stopped placing orders with Hydropath in 2009 and began to develop its own product. In 2012, Weatherford commenced proceedings against Hydropath for breach of warranty relating to the safety of the Clearwell Product.

The key questions to be determined by expert evidence were:

  • Was the Clearwell Product safe?
  • Had Weatherford and the other parties inappropriately used confidential information obtained from Hydropath when developing its own product from 2009 onwards?

Safety of the Clearwell Product

Weatherford and Hydropath each called two experts on the issue of whether the Clearwell Product complied with the European Directives for controlling explosive atmospheres (the Atex Regulations) and whether it was fit for purpose.

One of Hydropath's experts was described by the court as "nervous and inexperienced". His report did not comply with the requirements set out in Part 35 of the Civil Procedure Rules, and he admitted while giving evidence that other work he had been doing had got in the way of his preparation for this case.

He also had a change of opinion on the second day of giving evidence "in the shower before I got into my taxi this morning". He gave no reason for the change and this "seriously undermined his reliability" with the court.

Hydropath's other expert was inexperienced and Mr Justice Akenhead described him as "inadequately briefed."

Confidential information

Essentially the difference between the parties in respect of the use of confidential information was whether the circuit boards used in the Clearwell Product were similar to that used by Weatherford in their prototype replacement product "Clearwell R".

Mr Justice Akenhead found Hydropath's expert unhelpful on this issue. He criticised the expert's failure to analyse or explain the conclusions reached in his report and described his evidence as "bland assertions". Hydropath's Counsel were forced to "make bricks without straw" in their closing submissions, where they attempted to demonstrate that there must have been some copying of the Clearwell Product in the Clearwell R design, because the expert had failed to explain this in his oral evidence at trial. However, Mr Justice Akenhead said he was unable to "accept that approach without some intelligible support for this from the expert and there was no such intelligible support".

An expert needs to be fully prepared for a trial and may need assistance from his legal team on presentation such as avoiding inconsistencies in numbering within his report. In addition, in this case, Mr Justice Akenhead commented it was evident that the expert had not been provided with a number of key documents, such as witness statements, which addressed the design process for the Clearwell Product.

The poor performance of the Defendant's experts led Mr Justice Akenhead to accept the Claimant's case in its entirety. He concluded that the Clearwell Product was not safe and that the Claimant's Clearwell R product had not been developed using confidential information. He commented that "Lawyers and experts need to explain if necessary in words of one syllable all these various [technical] matters."

Previous decisions

Poor performance of experts is not a rare occurrence, as Mr Justice Akenhead made patently clear in some of his previous judgments:

  • In Igloo Regeneration v Powell William Partnership [2013] he described the claimant's engineering expert as inexperienced in comparable survey work and "over enthusiastic in his clients' cause" He considered its quantity surveying expert as "simply wholly unconvincing";
  • In Walter Lilly v Mackay [2012] he criticised the defendant's expert for his subjective approach in suggesting that aspects of the contractor's claim were not proved. He also disapproved of the experts' tendency to descend into "the arena of disputed facts and liabilities in which he was not the relevant expert" and in relying on conversations and information that was not in evidence; and
  • In National Museums and Galleries on Merseyside v AEW and PIHL/Galliford Try [2013] he described the defendant's experts as having given "little or no coherent thought to the issues in the case", being "argumentative if not combative, when cross examined", adopting a firefighting approach to "circumvent or soften" what others had said, and as tending to oversimplify matters. One of the experts even admitted to the court that he was "seeking to defend the indefensible."

It is clear from these comments that choosing the right expert is one of the most important decisions that a party will make when preparing a claim.

Choosing your expert

While no litigating party wishes to be on the receiving end of such judicial criticism, as most experts are instructed at the beginning of a dispute, usually before proceedings have even been issued, it can be difficult to identify so far in advance how an expert will perform at trial.

An expert who provides a clear opinion in support of your case at the pre-action stage may very well change his mind as further documents become available. Nerves or inexperience may get the better of an expert at trial and you can never be certain that an expert who is confident, articulate, and measured in a pre-trial meeting, will come across the same in the formal, alien setting of a courtroom.

However, there are a few key guidelines which, if followed when choosing your expert and when preparing your expert for trial, could assist in avoiding judicial criticism:

  • Spend time choosing an appropriate expert (and this might not necessarily be someone previously known, or who completely supports the case). Approach more than one expert. It will provide some comfort that the best/most appropriate expert has been chosen. Scrutinise their CV for evidence of previous court experience. Also, one positive side effect to this may be to conflict the other experts "beauty paraded."
  • Ensure the expert is adequately briefed, understands the requirements of Part 35 of the Civil Procedure Rules (the court rules dealing with experts), and has sight of and is familiar with all relevant documentation. The expert should also be familiar with the requirements of their professional body;
  • Witness familiarisation training may assist an inexperienced expert to appear less nervous when giving evidence. It will also encourage an expert to make appropriate concessions where necessary;
  • It is a long accepted principle that an expert may be qualified by experience as well as by professional qualifications. However whatever their experience, it is their independence that is the cornerstone of their credibility. In Weatherford, one of Hydropath's experts appeared to have produced a report in support of Hydropath's claim, which he could not explain or support at trial. It may not always be sensible to choose an expert who supports your case in its entirety. Such certainty from an expert is not necessarily reassuring and can suggest a lack of independence and an unwillingness to make appropriate concessions. This encourages the court to find that the expert is acting as an advocate for the party's case, forgetting his obligation to the court.
  • If an expert changes their mind prior to the trial, or indeed during the trial as happened in Weatherford, this will only undermine their evidence if they cannot provide clear reasons for the change. The problem for Hydropath was not that one of its experts had changed his mind, but rather that he did so without warning, which meant Hydropath's legal team had no opportunity to explain why he had done so to the court. For this reason, experts must be encouraged to be open as to their views and should be asked to report on each new document throughout the proceedings, and confirm whether or not their stance has changed as a result.

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