Expert witness duties in construction disputes

Party-appointed experts have become the norm in a wide-ranging field of expertise covering technical, scientific, legal and delay analysis, as well as valuation and quantum. The ultimate role of an expert witness is to provide a tribunal with an objective opinion on issues that are material to the outcome of the case as pleaded and beyond the tribunal’s own knowledge and expertise. Expert witnesses may be appointed by one or more parties or by the tribunal.

Given the increasing demand for expert evidence, both in civil procedure and commercial arbitration, it is more important than ever to recognise the duties of an expert witness, and what sanctions exist where an expert fails to perform those duties.

Attitudes to expert evidence

In very general terms, civil law systems do not accord party-appointed experts the same potential value, nor their evidence the same weight, as common law systems do. Traditionally, the latter tends to give considerable weight to expert evidence, while in the former, tribunals assume a more actively inquiring mandate and may accord less weight to the opinion of a party-appointed expert, who can be seen to lack neutrality and independence.

Where expert assistance is deemed necessary, an expert appointed by the tribunal is to be preferred.

When it comes to international arbitration a hybrid practice has evolved such that whatever the legal traditions of the arbitrator or arbitrators, a party-appointed expert will be viewed as acceptable although provision exists for a tribunal appointment.

Divergent sources of regulation

In common law jurisdictions, the general duties of an expert witness are established through a case law precedent system. In a civil law jurisdiction, however, those duties will be established by statute and interpreted by state courts on a case-by-case basis with due deference to any applicable general description of the duties by the jurisdiction's highest court.

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Most arbitration laws and rules are silent regarding the duties of expert witnesses during the arbitration proceedings. While some arbitration rules do address the role of a tribunal-appointed expert, the role of the party-appointed expert is often avoided. In practice, rules and practice surrounding expert evidence are generally left to be established by the arbitrators or the parties. A useful source of guidance in this respect may be found in non-binding publications.

One of the most internationally recognised and widely used ‘soft law’ instruments is the International Bar Association (IBA) Rules on the Taking of Evidence in International Arbitration. Articles 5 and 6 of the IBA Rules on party-appointed and tribunal-appointed experts respectively, supplemented by Article 8 dealing with procedural aspects of oral testimony at the evidentiary hearing, provide a comprehensive framework for use and management of evidence from expert witnesses.

Prior to the publication of the IBA Rules, parties to international arbitrations also referred to the London-based Chartered Institute of Arbitrators’ (CIArb) Protocol for the Use of Party-Appointed Expert Witnesses in International Arbitration. That protocol establishes a regime for the giving of evidence by party-appointed experts and provides a procedure for the independence of the experts, the contents of the expert's opinions and the manner of expert testimony.

To take a national example, the Spanish Arbitration Club has published a Code of Good Arbitral Practices aimed at ensuring that all participants in the arbitral process adhere to increasingly demanding standards of independence, impartiality, transparency and professionalism. This code devotes two entire sections to experts’ duties. In addition to these soft law instruments, professional expert witnesses may join professional bodies and organisations with established codes of conduct setting out ethical rules for their members when serving as witnesses in dispute resolution proceedings. This is particularly the case for construction and engineering professionals.

An expert witness’s main duties

Expert witness duties refer to the legal and ethical responsibilities that an expert witness must fulfil to provide reliable and trustworthy testimony to the court or to an arbitral tribunal in a legal case. Whether in a civil or common law jurisdiction, the main duties on experts are generally the same. An expert must have a certain degree of expertise. Broadly speaking, experts fall into four main categories:

• technical or scientific experts;
• legal experts;
• delay experts; and
• valuation or quantum experts.

As the role of the expert is to opine on material issues that require the application of knowledge and expertise that the tribunal lacks, in order to assist the tribunal to form an opinion on those issues, it is important that the tribunal recognises the relevance and value of the expert’s knowledge, qualifications, training and experience.

Experts must also be exceptionally qualified in the specific subject matter on which they are going to give an opinion. For example, under Spanish law, “experts must have the official qualification that corresponds to the subject matter of the report and its nature. In the case of matters which are not covered by official professional qualifications, they shall be official qualifications, they shall be appointed from among persons knowledgeable in those matters". Under French law, in order to be registered in the list of potential court appointed experts, the expert must submit an annual declaration informing of the training courses they have followed in the past year and mentioning the organisations that have provided them.

The expert must also express their own opinion without fear or favour, regardless of which party or parties appointed them. Party-appointed experts are, above all, witnesses. As with any other witness, the tribunal may reasonably expect and require that an expert tell the truth when they testify. The expert's duty to testify truthfully overrides any other duty that an expert might believe that they owe to a party. Generally, an expert will be invited to state under oath or to make a formal promise that they will tell the truth, assist the tribunal, act as objectively as possible and give their opinion based on their honour and good conscience.

The expert must be impartial and independent and must assess the case in a neutral and objective fashion. All experts must be, to some extent, independent from the parties as well as their legal advisors and the members of the tribunal. To ensure this, they should disclose any previous or current relationship that they might have.

In some civil law jurisdictions, specific rules have been implemented aimed to ensure expert impartiality in certain circumstances. For example, in order to guarantee due impartiality, the Spanish Civil Procedure Act states that: "unless otherwise agreed by the parties, an expert who has been involved in mediation or arbitration related to the same matter may not be asked for an expert's opinion". Under French law, a court-appointed expert cannot receive any remuneration directly from a party, in any form whatsoever, even by way of reimbursement of expenses – except by decision of the judge.

Experts are usually bound to attend the hearing if their attendance is requested, failing which they may be disqualified, and their testimony may not be given full weight or struck off the record. Another expert duty is to respect deadlines set by the tribunal. In the same spirit, an expert must respect the limits of the assignment that they have received and may not go beyond its scope. Finally, confidentiality is sometimes one of the experts’ duties. An expert must not divulge confidential information and trade secrets of the counterparty.

Possible sanctions

A breach of expert witness duties can have serious consequences for both the expert witness and the legal case in which they are involved. Consequences can vary depending on the jurisdiction and the specific circumstances of the breach. However, there are some similar consequences in a court case and arbitral proceedings.

An expert can be challenged by the parties and disqualified. The tribunal can limit or exclude the expert’s report and/or testimony if it is found that their breach of duties has had a significant impact on the case. The most common grounds to disqualify an expert are the lack of independence of the expert and/or the existence of clear conflicts; the lack of qualification and expertise, and the expert’s failure to appear and/or non-delivery of the required opinions or reports. It is worth noting that, in the case of party-appointed experts, disqualifying the expert can be delicate as it affects the appointing party’s right to adduce expert evidence.

In judicial practice, an expert who has breached their duties may be held civilly and/or criminally liable. If it is proved that the expert breach of their duties has caused a damaged to one of the parties in the proceedings, the expert might be ordered to indemnify the injured party. In some jurisdictions, such as England & Wales, an expert may be found liable in tort for a negligent misstatement. In some civil law jurisdictions, an expert who breaches their duty of loyalty to the truth – which is imposed by the criminal laws – can also be prosecuted for giving false testimony.

Other consequences can include loss of credibility and damage to the expert’s professional reputation, which will make it difficult for them to find work as an expert witness in future cases. The expert witness may also face disciplinary action from their professional regulatory body if they breach professional codes of conduct or ethical guidelines.

Risk management

The precise contours of the applicable duties of an expert witness will differ from legal system to legal system. Still, engaging an expert witness of repute on behalf of a client does not detract from the duty that a lawyer owes to his or her client to possess, and where necessary apply, a working knowledge of the expert witness’s precise duties owed to the tribunal and to the parties; and of the potential legal consequences arising from a failure to discharge them.

Further, the production of clear terms of engagement, clear instructions, a clear record of submissions identifying the ‘issue for expert opinion’, and a clear supporting evidential record will go some way toward avoiding wasteful confusion and errors. These usually are matters involving dealings between experienced professionals, and the expert owes a duty to ensure that their commission is clearly and comprehensively documented before they give a reasoned opinion.