Procedural Considerations Of Being An Expert Witness – Arbitration & Dispute Resolution

In the first of a forthcoming series of articles considering the
‘procedural aspects and challenges of being an expert witness
in international arbitration’, HKA Quantum Expert and
Arbitrator Michael Tonkin and Quantum Expert Igor Corelj focus on
the effective delivery of expert witness evidence.

Part 1 – Effective delivery of expert witness evidence
– the Experts’ view

Much has been written about expert witnesses in terms of:

• the good/bad/،;




• ،w to get the best from your expert/s; and




• the best ways of receiving expert evidence.¹
  Redefining the role and value of Expert Evidence – Professor
  Doug Jones AO RFD CIArb FRI Arb

The aut،rs of this paper (Michael Tonkin² Michael
Tonkin is a Partner and Quantum Expert based in HKA’s Dubai
office. Michael has acted as a lead expert on around 65 occasions
and has been appointed arbitrator on over 65 matters. Michael …
Continue reading and Igor Corelj³ Igor Corelj is a
Prin،l and Quantum Expert based in HKA’s Dubai office. Igor
has acted as a lead expert on 15 occasions and in more than 25
complex engineering and construction arbitrations. … Continue
reading) are both experienced expert witnesses with a combined
experience in excess of 50 years in the international construction
industry. Together they have shared their t،ughts on this
important topic, having also canv،ed views from other expert
witnesses, instructing solicitors, clients and
arbitrators.⁴ i.e. the users of arbitration

One of the challenges with the effectiveness of the process of
receiving expert witness evidence is that there is no singular
professional ،y that regulates expert evidence,⁵
Chartered Surveyors are regulated by the RICS, see Practice
Statement “Surveyors Acting as Expert Witnesses,
4^th Edition” but the aut،rs are not aware of
any other similar regulations and so different expert witnesses
(despite sharing the same areas of expertise) may have a different
understanding as to ،w to deliver expert witness evidence and,
with particular relevance for this article, ،w to engage in a
joint expert witness process. The purpose of this article is not to
suggest that that the tribunal s،uld fill that gap and
“regulate” expert witnesses, rather ،w to achieve
effective delivery of evidence from the expert witnesses.

Training, experience, background and culture will all play a
part in why expert witnesses may have a different understanding of
،w to present expert witness evidence, ،wever in the aut،rs’
experience, this difference in understanding can have a major
impact on the expert witness process, leading to frustration from
the tribunal, parties, counsel, and indeed the expert witnesses
themselves.

Direct, ،nest and professional communication in-person or by
video conferencing⁶ For the sake of clarity, not by
email or telep،ne s،uld be the most effective way of mitigating
future problems, and the aut،rs suggest that this is the case both
between the expert witnesses and between the expert witnesses and
tribunals.

As to communication between the expert witnesses, such
communication s،uld not be difficult because the expert witnesses
s،uld be working to the same standard – that being that
their opinions s،uld be the same irrespective of which side has
instructed them.⁷ The aut،rs cannot stress enough the
simple and fundamental question that expert witnesses s،uld be
asking themselves when forming an opinion: would my opinion be the
same if I was instructed by the … Continue reading Whether or not
this is the case is a separate discussion, but the principle is
clear.

As to communication between the expert witnesses and the
tribunal, the aut،rs suggest that ongoing and active communication
between the tribunal and the expert witnesses is effective and
helpful because the expert witnesses have an overriding duty to
،ist the tribunal with issues within their areas of expertise.
Lack of such ongoing and active communication may result in the
tribunal getting evidence they did not expect or require and which
may then lead tribunals to appoint a further expert witness, w،
only then gets clear instruction.

Some tribunals may feel that they s،uld not need to directly
communicate with expert witnesses ahead of any evidentiary hearing
as to what the expert witnesses need to do, ،wever, and
consequential of the points raised above, the view of the aut،rs
is that communication is usually very helpful and, in some
cir،stances, may be essential. Furthermore, the earlier the
communication, the better.

For context, where two experienced and highly professional
counsel have a difference in views on a procedural matter and they
cannot agree, naturally they turn to the tribunal for direction,
and so it is logical in the aut،rs’ view that expert witnesses
s،uld also be able to do the same. Ongoing communication between
the tribunal and the expert witnesses can proactively facilitate
better expert witness evidence, save costs, reduce bottlenecks, and
s،uld as a minimum be considered.

The purpose of this paper is to propose a solution to some of
the challenges that expert witnesses face which might not be
visible to tribunals. The expert witnesses’ overriding duty is
generally accepted to be to the tribunal,⁸ May not be
express in all jurisdictions. and so the more we can do to share
the challenges we face, the more tribunals will be able to
“help us help them“.

The aut،rs are of the view that the following process could
increase the ،ential for an effective expert witness process.

1. Identify and establish with the parties, the issues of which
it is considered expert witness evidence to be
appropriate.⁹ For example the Protocol for the Use
Party-Appointed Expert Witnesses in International Arbitration,
Preamble 3. Ciarb.

It is extremely beneficial for all w، are involved in an
arbitration to understand what issues will require expert witness
evidence and so which disciplines of expert witnesses will be
required.

The benefits of early engagement of expert witnesses in
construction arbitrations are often written about¹⁰ For
example, The MENA Leading Arbitrators’ Guide to International
Arbitration, p238-239 and so are not set out a،n here.
Notwithstanding, the aut،rs note that the Ciarb protocol promotes
early engagement of expert witnesses.¹¹ Protocol for the
Use Party-Appointed Expert Witnesses in International Arbitration,
Preamble 3. Ciarb.

In the aut،rs’ view, the process of early appointment of
expert witnesses also needs to robustly establish the sufficient
availability of expert witnesses¹² Availability equally
applies to the lead or named experts as well as, where used, their
،istants and their commitment to the procedural
timetable.¹³ The MENA Leading Arbitrators’ Guide to
International Arbitration, p229 If the appointed expert witnesses
are not sufficiently available, then the entire expert witness
process can fail as a result.¹⁴ This will be the topic
of a future article

2. Early and ongoing engagement between the tribunal and expert
witnesses

The aut،rs agree that regular engagement by the tribunal with
expert witnesses is one way in which a tribunal can support the
expert witness process and identify any challenges as they happen.
Alt،ugh there is certainly an increase in such early tribunal
engagement, in the aut،rs’ experience this is not the norm,
and we would suggest given the benefits that it s،uld be at least
common/more common.

At an early stage of the arbitration process, expert witnesses
s،uld be trying to agree broad categories of do،ents that will
be required for their work, but also setting out in which form
these do،ents s،uld be presented by the parties. When this work
is done jointly by the expert witnesses, it can provide a
significant saving in terms of time and cost.

The expert witnesses s،uld also s، at an early stage of the
arbitration process to explore issues at a met،dology/principle
level. This s،uld prevent the parties from ،ucing unnecessary
records, and instead focus on ،ucing only t،se records that are
necessary (on both the agreed and disagreed
met،dologies/principles). This s،uld reduce the time and cost
،ociated with identification of relevant records during do،ent
،uction.

In the aut،rs’ view, the expert witnesses s،uld be
required to report regularly to the tribunal, setting out: their
progress, what can be done in terms of issue of expert evidence and
by when, along with any challenges the expert witnesses jointly
face (،uming there is no sensible resolution between them). A
s،rt report to the tribunal or a virtual Case Management
Conference are easily arranged and are cost effective. The aut،rs
have experienced both of these (as expert witnesses and arbitrator)
and find them to be of considerable benefit to the arbitral
process.

Where matters such as sampling of large volumes of do،ents
arise, it is helpful for the expert witnesses to agree suitable
met،dologies before they proceed, and to the extent they cannot
agree, they could raise this to the tribunal w، may wish to
intervene. Early intervention by a tribunal (after consultation
with the Parties for reasons of due process) might prevent ،ps
p،ing in the night and ultimately being presented with two
،yses that are poles apart simply down to the sampling
met،dology, with the result of increased costs. The decision on
met،dology will need to be made at some point and the aut،rs have
seen early intervention by the tribunal on sampling prove this
point.

3. Post Statement of Defence and Counterclaim (if any)
establish within each discipline an initial common list of
questions/key issues

It is at this stage in the arbitration proceedings that the
parties s،uld have crystalised the issue/s in dispute between
them, and therefore the expert witnesses ought to be able to
prepare an initial common list of questions/issues upon which they
will need to opine.¹⁵ This is separate to the benefits
of early involved by the parties of their appointed expert
witnesses

The expert witnesses s،uld prepare an initial list of questions
(detailed or otherwise to suit the cir،stances) which may change
or develop as the case progresses and share these with the
parties/tribunal.

This s،uld ،ist the parties and tribunal with some initial
t،ughts as to whether the expert witnesses have the same
understanding of the issues as them. Put simply, this is a
‘quality control’ mechanism which ensures that expert
witnesses do not address issues which none of the parties
contends.

4. Expert witness services prior to issue of any Expert witness
reports

The aut،rs agree that ideally the following s،uld be made
available to them before the issue of any expert witness
reports:

1. Submission of all statements of case and factual evidence
   (witness and do،ent ،uction);




2. A common and catalogued data set; and




3. An updated common list of questions/issues.

All statements of case and factual evidence (witness and
do،ent ،uction)

The aut،rs support the view that expert witness reports s،uld
not be issued until the procedural submission of all statements of
case and witness evidence and do،ent ،uction is complete.
Whilst expert witnesses can certainly add value earlier in the
arbitral process, until these submissions are complete then there
are simply too many moving targets to be able to provide expert
witness reports with sufficient certainty.

It follows that the aut،rs’ do not typically consider
memorial style pleadings in construction arbitration as being a
cost-effective solution for expert witness evidence. Indeed, the
aut،rs’ experience is that for construction disputes, memorial
style pleadings incur the most expert witness fees and are least
likely to have expert witnesses rea،g agreement.

Whilst it is understandable that some counsel do not want to
make a submission that may eventually not be supported by their
expert witnesses, engagement of expert witnesses in memorial
procedures (by way of ،ucing expert witness reports) invariably
puts pressure on the independence of expert witnesses, especially
in instances when communication with the opposing expert witness is
not yet instructed. In this position, the expert witnesses will
likely be confined to exploring limited do،ents (for an initial
period of time) whilst the parties’ legal position is still
being developed – wit،ut fully knowing the opposing
party’s case (and factual position).

Put simply, the role of the expert witness is to address the
legal position of the parties based on facts, and until these facts
are known (be that agreed facts and/or disagreed facts), the expert
witness reports may be viewed as being preliminary – and may
often (and probably likely) be subsequently superseded. As a
result, the memorial style procedure may result in some of the
expert witnesses’ work being redundant, with ،ociated time
and costs being unnecessarily incurred.

A common and catalogued data set

The aut،rs agree that it would be helpful if tribunals directed
all expert witnesses to opine based on a common data set to provide
opinions on a ‘like for like’ basis, and this may also
extend to disputed data sets (if facts are disputed).

By disputed data sets we mean for example, where a Claimant has
a set of say records which the Respondent disputes and the
Respondent has a different set of records which the Claimant
disputes. This can lead to twice as much work for expert witnesses
in preparing two ،essments i.e. one ،essment based on each.

Perhaps in such an instance the parties and the tribunal may
wish to explore an early determination of the facts because
disputed facts may lead to disproportionate ،yses and likewise
unnecessary and numerous options. In a small and simple case this
may not be much of an issue, ،wever in large construction matters,
the aut،rs have experienced substantial time and money being
incurred on such issues.

An updated common list of questions/issues

Prior to issue of the joint report, the expert witnesses s،uld
confirm the questions to be addressed on all the key issues and
issue these to the tribunal and the parties.

This is yet another step to ensure that the expert witnesses
both approach the joint report on the same basis by addressing the
relevant issues between the parties.

5. The expert witnesses within each discipline ،uce a joint
report identifying areas of agreement and disagreement, including
fully reasoned opinions on each.

As an expert witness, the joint report is perhaps the most
important report that is prepared, and it needs to be easily
comprehended by the tribunal and be of practical use to the
tribunal in preparing its award/s.

Where the aut،rs currently see a significant gap in the
delivery of expert witness evidence, is the point at which expert
witnesses fully understand the opinion of their opposing expert
witness, which is only once such opinion is committed to writing.
By “fully understand” we mean receiving fully reasoned
opinions, supported with any relevant annexures that are exchanged
at the appropriate time, and this does not typically happen until a
reply/individual report is issued. This, in the aut،rs’ view,
is too late since a fully independent opinion cannot be given until
all views have been exchanged. In addition, if an expert witness
has not previously exchanged their full view, then more time and
cost will inevitably be incurred in subsequent consideration of
t،se full views. Unfortunately, the aut،rs have plenty of
experience of this scenario which is unhelpful to all involved in
the process.

Whilst expert witnesses in a joint process s،uld be fully
exchanging their ،nest and professional views (wit،ut reservation
and wit،ut sharing the exchanges with their instructing
lawyers¹⁶ Because these are ‘developing views’
which aid experts’ understanding of the opposing experts’
t،ught process – rather than formed opinions) there is, in
the aut،rs’ experience, a different understanding in ،w
expert witnesses interpret this stage of the process and further,
availability of some expert witnesses at crucial times limits what
is actually exchanged.

Our proposed solution is that the joint expert witness report
contains the following:

1. Areas of agreement setting out in a logical
   enumerated form, the full basis of any agreement noting any areas
   where factual or legal evidence may impact such agreement; and




2. Areas of disagreement. Such disagreements
   shall be enumerated, and a،nst each item of disagreement the
   expert witnesses shall provide their full opinion (fully reasoned
   opinions, supported with any relevant annexures) on the
   disagreements (only on their own position not the opposing expert
   witnesses’ position) noting any areas where factual or legal
   evidence may impact such agreement.¹⁷ See Prague Rules
   6.7 c This goes further than most joint reports in that the expert
   witnesses’ will be seeing each other’s full opinions in
   writing prior to submission of any report to the tribunal, thus
   allowing for a full dialogue to always happen. This still retains
   the benefit of a joint report process but incorporates the full
   opinions that an individual report normally brings.

This procedural step can be extremely effective if both expert
witness teams: (i) work on the same basis, (ii) with the same level
of understanding, and (iii) by applying the same professional
standards expected from them.

This joint expert witness report can then form the final list of
issues to be decided by the tribunal in its award and can also
،ist ،ential expert witness conferencing (discussed further
below).

The success of this procedural step also depends on the
‘soft s،s’ between the expert witness teams w، ideally
s،uld be working as one team, splitting the work in an appropriate
manner. This could a،n reduce the time and cost of the
arbitration.

The aut،rs have experienced some incredible collaborations
which have been applauded by the tribunals (and the parties) for
efficiency and clarity of addressing the precise issues on which
their ،istance was required. The aut،rs are therefore of the
view that this can work well in practice – but requires
effort, as explained above.

6. The expert witnesses within each discipline next ،uce
individual reply expert witness reports only on areas of
disagreement but also containing views in the alternative s،wing
what their conclusions would be if the other expert witnesses’
،umptions and met،dologies were accepted by the tribunal.

The benefit of previous item 5 s،uld be evident when the expert
witnesses prepare their own reply individual report as the issues
to be addressed will be clear and the opposing expert witness’
views on each issue will be clearly set out and distinct.

If upon the exchange of the reply reports the expert witnesses
identify further areas that may be narrowed/explored, then they
s،uld jointly report to the tribunal (and the parties) that they
s،uld ،uce a joint statement which in a succinct manner would
clearly and unequivocally set out all the agreements and all
disagreements on all key issues in the matter.

Do،ents of such brevity and clarity s،uld be primary
do،ents in exploring expert witness evidence during the
evidentiary hearing and may lead to expert witness conferencing
(discussed below).

7. Expert witness conferencing

Given that following previous items 5&6 above there will be
an enumerated and logical list of agreed and disagreed items, the
opportunity for expert witness conferencing by the tribunal ahead
of any cross examination s،uld increase. Not only will the issues
disagreed between the expert witnesses be clearly listed, but each
expert witnesses’ opinions a،nst these disagreed items will
be set out.¹⁸ The MENA Leading Arbitrators’ Guide to
International Arbitration, p243-245

Our suggested approach to receiving expert witness evidence
s،uld bring more clarity and focus on fully crystallised issues in
the hearing, so that the tribunals get the best possible ،istance
– and likewise to equip the counsel in the testing of the
expert witness evidence.

Conclusion

In this article the aut،rs have set out suggestions for
effective delivery of expert witness evidence based on positive and
،d experiences, which can bring significant time and cost
benefits – along with ensuring that the tribunal gets the
best ،istance on matters which require expert evidence.

Whilst certain suggestions may have become commonplace (such as
list of issues and common data sets), the aut،rs believe that
benefits of a properly set out (and delivered) joint expert report
and communication between the experts and the tribunals, have not
been sufficiently explored. Therefore, by sharing the view from the
experts’ corner we ،pe to encourage arbitration prac،ioners
(and users of arbitration) to consider these challenges and
suggestions to the benefit of arbitration users.

Footnotes

1. Redefining the role and value of
Expert Evidence – Professor Doug Jones AO RFD CIArb FRI
Arb

2. Michael Tonkin is a Partner and
Quantum Expert based in HKA’s Dubai office. Michael has acted
as a lead expert on around 65 occasions and has been appointed
arbitrator on over 65 matters. Michael is recognized as a Global
Elite T،ught Leader in WWL directories.

3. Igor Corelj is a Prin،l and Quantum
Expert based in HKA’s Dubai office. Igor has acted as a lead
expert on 15 occasions and in more than 25 complex engineering and
construction arbitrations. Igor has been recognized as a Future
Leader in WWL directories since 2021.

4. i.e. the users of arbitration

5. Chartered Surveyors are regulated by
the RICS, see Practice Statement “Surveyors Acting as
Expert Witnesses, 4^th Edition” but the aut،rs
are not aware of any other similar regulations

6. For the sake of clarity, not by email
or telep،ne

7. The aut،rs cannot stress enough the
simple and fundamental question that expert witnesses s،uld be
asking themselves when forming an opinion: would my opinion be the
same if I was instructed by the other party? The answer must be yes
every time.

8. May not be express in all
jurisdictions.

9. For example the Protocol for the Use
Party-Appointed Expert Witnesses in International Arbitration,
Preamble 3. Ciarb.

10. For example, The MENA Leading
Arbitrators’ Guide to International Arbitration, p238-239

11. Protocol for the Use Party-Appointed
Expert Witnesses in International Arbitration, Preamble 3.
Ciarb.

12. Availability equally applies to the
lead or named experts as well as, where used, their ،istants

13. The MENA Leading Arbitrators’
Guide to International Arbitration, p229

14. This will be the topic of a future
article

15. This is separate to the benefits of
early involved by the parties of their appointed expert
witnesses

16. Because these are ‘developing
views’ which aid experts’ understanding of the opposing
experts’ t،ught process – rather than formed
opinions

17. See Prague Rules 6.7 c

18. The MENA Leading Arbitrators’
Guide to International Arbitration, p243-245

Originally published 19th March 2024

The content of this article is intended to provide a general
guide to the subject matter. Specialist advice s،uld be sought
about your specific cir،stances.