August EWJ 24 - Flipbook - Page 97
expert’s evidence as there is no right to serve
adversarial evidence contradicting or disagreeing with
the joint expert, who may simply be wrong in their
conclusions. This usually means the party whose
case the expert does not support will seek to instruct
their own expert, resulting in a lengthier and more
expensive process.
uninfluenced by the pressures of the dispute resolution process or
by any Party… An expert’s duty, in giving evidence in the Arbitration, is to assist the Arbitral Tribunal to decide the issues in
respect of which expert evidence is adduced.” Other guidelines
include the IBA Rules on the Taking of
Evidence in International Arbitration 2020 (Articles 5
and 6), UNCITRAL Notes on Organising Arbitral
Proceedings 2016 (paragraphs 92 to 107), and the
ICC Techniques for Controlling Time and Costs in
Arbitration 2012 (paragraphs 62 to 68).
‘Hot tubbing’
Traditionally experts would give evidence separately
as one of the various witnesses that a party calls whilst
it presents its case. Not, only would this mean that the
respondent’s expert might be heard days or weeks
after the claimant’s expert, making it difficult to do a
direct comparison in respect of their answers on the issues, but cross-examination can often blur the issues
or create confusion in the mind(s) of the tribunal. Further, experts may be seen as partisan, or biased, or the
evidence may appear too technical and not properly
establish the information or context that a tribunal is
looking for.
Exchange of expert evidence
Once the scope of expert evidence is contained in a
procedural order, parties generally have a window of
time to find and instruct an expert. This can take time,
as conflict checks need to be conducted, fees agreed
and instructions sent. The expert then needs time to
assess the available information, ask for clarifications if
necessary, and draft their report by the deadline
stipulated in the order.
Expert evidence can initially be given either simultaneously, where the parties swap their reports at the
same time, or consecutively, e.g. the claimant serves
their report first, following which the respondent has
a period of time to file a response.
To counter this, it is not uncommon for the tribunal to
order at some point towards the end of the final hearing that the two experts be questioned at the same
time, thereby generating a discussion on the technical
issues. This is formally called ‘witness conferencing’,
or more informally as ‘hot-tubbing’. ‘Hot tubbing’ as
a concept is widely accepted to have originated in Australia in the 1970s but has become more prevalent
since then. It is more commonly used in some countries over others in both litigation and arbitration and
many practitioners consider ‘hot tubbing’ to provide a
more satisfactory expert witness experience.
The experts may then meet to discuss their reports
and/or produce a joint report in which they identify
and explain areas of agreement and disagreement.
The adversarial and joint reports are included in the
bundle for the evidentiary hearing, at which the experts may give evidence and be cross-examined individually or together (so-called ‘hot tubbing’ or witness
conferencing).
As with the joint expert report, areas of agreement can
arise quickly during such a discussion, and differing
views can be analysed point-by-point. Expert evidence
lends itself to witness conferencing much more than
evidence of fact because experts give evidence based
on their professional opinions and experience, and
reasonable experts can disagree on the same point.
With the parties’ input, the tribunal may give standard
directions on the use of expert evidence in the arbitration, with more detailed specific directions in cases
of witness conferencing.
Single joint experts and joint reports
Although rare, there are benefits to the parties
instructing a single joint expert to deal with the issues.
A single expert will be cheaper, and will not need to
spend time interacting with any other experts. Once
the single joint expert produces a report, all of the
parties know the full extent of the expert evidence and
can rely on it (in the absence of its own expert, the tribunal’s questions of the single joint expert will be
narrow).
It is not without its problems, however. A party
considering ‘hot tubbing’ will want to ensure it has a
good expert. Experts differ in their comfort around
peers who may disagree strongly with their professional judgment. Practically, some people will speak
more loudly and with more force than others; debate
between experts can descend into detail too fine for
the matters in dispute, or otherwise become irrelevant.
Many of these concerns can be addressed by the parties and tribunal via strict ground rules on speaking;
these should be contained in specific directions.
If appointed, the single joint expert will only engage
with the parties and tribunals in ‘open’ communications, meaning there is no scope for communication
hidden from the other party or the tribunal (in English law and procedure, there can be Without Prejudice or Without Prejudice Save As To Costs
communication with a single joint expert).
The future of experts and expert evidence in
international arbitration
As shown above with the development of witness
conferencing, the way experts give evidence has
changed over the years, but what does the future
hold?
However there are challenges which mean single-joint
experts are rarely used. The parties may negotiate
fruitlessly over the identity of the single joint expert,
given their conflicting interests in what the expert may
say. It is also difficult to counter the single joint
EXPERT WITNESS JOURNAL
In 2018, the LCIA produced a Note on Experts
in International Arbitration that indicated future
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