Mike Allen (Managing Director, Secretariat) gives the expert's view. The slides in this segment are topics and questions for him to take up, change or drop; nothing on them is a view attributed to him. They ask what an expert needs from the legal team, how an expert's independence holds up under pressure from the people who instruct and pay him, and what makes a joint meeting between experts work.
What the expert needs from the legal team
The first set of questions is about what an expert needs from the lawyers who instruct him. Three things come up in every case: instructions and a list of the issues, the documents, and time.
On documents the law is settled. In Kennedy v Cordia the Supreme Court put the duty on the legal team. It must give the expert the material that points the other way, as well as the material that supports the client's case [57]. In ICI v MMT Fraser J said that experts of like discipline should have access to the same material [237].
On time, CIArb's 2026 Report on party-appointed experts found a gap in perception. Asked whether the parties and tribunals give experts enough time for their work, 77% of arbitrators said yes, and 44% of experts. The Report also found that experts are seen mainly as report writers rather than as early advisers who can shape the issues and test the claim. Its survey had 419 respondents, and the Report says its findings are perceptions, not measurements.
“That should include not only material which supports their client's case but also material, of which they are aware, that points in the other direction”
“Experts of like discipline should have access to the same material.”
“77% of arbitrators, 44% of expert witnesses, 66% of external counsel, and 80% of in-house counsel consider that the parties and/or tribunals give expert witnesses enough time to carry out their work”
“Expert witnesses are therefore seen primarily as report writers, rather than as early strategic advisors who can shape issues, test claims, and identify technical weaknesses”
Independence under pressure
The second set of questions is about independence when the pressure is on. CIArb's 2026 Report defines over-instruction as instructions that improperly shape, constrain or direct an expert's opinions so as to compromise, or appear to compromise, the expert's independence (para 5.1.1). Its survey found what it calls one of the starkest splits in the data. Among arbitrators, 66% said experts are often or very often over-instructed by counsel. Among experts, 73% said this happens never or not often. The Report offers two possible explanations: experts' professional autonomy and adherence to ethical standards, or an underestimation of the subtle procedural and strategic pressures of the party-appointed model. The questions for the expert are who is seeing it wrongly, what pressure looks like in practice, and how an expert refuses the client who pays.
The third question is about changing view. In Guntrip v Cheney Coaches the Court of Appeal said that an expert who can no longer support the case of the person who instructed him has a duty to say so [17]. The sooner he says so the better [21]. The Ikarian Reefer duties say the same: a change of view after reports are exchanged must go to the other side, through the lawyers, without delay. Under the CIArb Protocol the expert's declaration confirms that he has drawn to the tribunal's attention all matters he is aware of that might adversely affect his opinion (art 8(d)). For RICS members, the fifth edition of Surveyors acting as expert witnesses comes into force on 30 November 2026. It says members must not allow themselves to be limited, influenced or directed by those instructing them (s 4.4.5).
“a divergence that represents one of the starkest role-based splits in the entire data set.”
“If at any time the expert can no longer support the case of the person who instructed him, it is his duty to say so.”
“5.1.1 Over-instruction occurs when the instructions given to an expert witness improperly shape, constrain, or direct the expert witness's opinions in a way that compromises, or appears to compromise, the expert witness's independence and objectivity.”
“an underestimation of the subtle procedural and strategic pressures”
“I confirm that I have referred to all matters which I regard as relevant to the opinions I have expressed and have drawn to the attention of the arbitral tribunal all matters, of which I am aware, which might adversely affect my opinion.”
“if an expert changes his mind about the merits of a claim, the sooner he says so the better.”
Joint meetings without counsel
The last set of questions is about the experts' joint meeting and the joint statement that comes out of it. The rules are short. In England the TCC Guide says the legal advisers must not negotiate, draft or revise the experts' joint statement, directly or through their expert (para 14.6.3). In Hong Kong, Lam J said in Chinachem that an expert need not seek instructions from his client before agreeing a point within his expertise with the other side's expert. Nor is it proper for lawyers to give an expert that instruction [490]. The Code of Conduct in the Rules of the High Court says the same for court experts (App D para 13).
The Society of Construction Law (Singapore) published a protocol on joint statements in January 2026. Under it the experts declare that they were not instructed to avoid or defer agreement, and counsel must not be involved in negotiating or drafting the statement. CIArb's 2026 Report suggests a procedural order in the same terms, and found a weighted 84% of respondents in favour of little or no counsel involvement.
The questions are what makes two experts agree, what stops them, whether experts should meet early on common data and methodology before they write, and what the joint statement should explain. On the early meeting, 81% of arbitrators and 81% of experts in the CIArb survey said the tribunal should require it. On the last point, Lam J said in Chevalier that it is not enough for an expert to record that he disagrees: he should explain intelligibly why [5].
“It takes two to tango.”
“Counsel shall have no involvement in the drafting, negotiation or substantive content of any joint expert witness report.”
“On matters within his expertise, an expert needs not seek instructions from his client before reaching an agreement with the other side's expert.”
“It is not good enough for an expert to state in a joint report that he disagrees with the other expert. He should explain intelligibly why he disagrees.”
“81% of arbitrators, 81% of expert witnesses, 90% of external counsel, and 83% of in-house counsel agree that the tribunal should require the expert witnesses to meet at an early stage”
“the Parties' counsel must not be involved in the process of negotiating or drafting the Experts' Joint Statement”
Go deeper
Kennedy v Cordia (Services) LLP
[2016] UKSC 6 · UKSC · Lord Reed and Lord Hodge (Lady Hale, Lord Wilson and Lord Toulson agreeing) · 10 February 2016 ·Find Case Law
[38] Four matters: admissibility; legal team's responsibility to keep expert to role; court's policing of duties; economy.
[44] Four considerations governing admissibility of skilled evidence: assistance; knowledge and experience; impartiality; reliable body of knowledge.
[48] Expert must explain the basis of evidence; bare ipse dixit is worthless; what carries weight is the reasoning.
[49] Expert must not supplant the court as decision-maker; may sometimes address the ultimate issue.
[51] Independence and impartiality go to admissibility, not merely weight (citing Toth v Jarman [100]-[102]).
[52]-[53] Quotes Cresswell J's Ikarian Reefer list (pp 81-82) omitting case citations; adopted for Scotland.
[57] Counsel and solicitors must check expertise and admissibility, make sure expert knows the duties, and disclose relevant material including material pointing the other way.
Judgments of the courts of England and Wales are quoted from Find Case Law under the Open Justice Licence v1.0.
Imperial Chemical Industries Ltd v Merit Merrell Technology Ltd
[2018] EWHC 1577 (TCC) · TCC · Fraser J · 21 June 2018 ·Find Case Law
[184]-[187] Quantum expert decided for himself a contract interpretation (actual cost not schedule of rates) and argued it: not acceptable for an independent expert.
[197]-[199] Expert took and created positions on disputed facts in his client's favour; evidence prepared without sufficient attention to the duty to the court.
[233]-[236] All of one party's experts found lacking in independence; 'remarkable' if coincidence.
[237] Six practical rules applying the Ikarian Reefer: same material for like experts; no choosing between versions of fact; no partisan stance on interlocutory applications; joint process constructive and proportionate; notice of late analysis, no surprise reports during trial; no loosening of the principles. Lawyers must explain the principles.
Judgments of the courts of England and Wales are quoted from Find Case Law under the Open Justice Licence v1.0.
Guntrip v Cheney Coaches Ltd
[2012] EWCA Civ 392 · EWCA · Lewison LJ (Elias LJ and Ward LJ agreeing) · 14 March 2012 ·Find Case Law
[17] Approves Stallwood [17]; overriding duty applies to the joint statement; if the expert can no longer support the case he must say so; courts discourage expert shopping; a change of view is not enough to justify a new expert; points from a new expert can still be put in cross-examination.
[21]-[27] District judge entitled to refuse a change of expert after an adverse joint statement; appeal allowed.
Judgments of the courts of England and Wales are quoted from Find Case Law under the Open Justice Licence v1.0.
Chinachem Charitable Foundation Ltd v Chan Chun Chuen and another
[2010] HKCFI 88 · Court of First Instance, Hong Kong · Lam J (M H Lam J) · 2 February 2010 ·Source
Chevalier (Construction) Co Ltd v Tak Cheong Engineering Development Ltd
[2011] HKCFI 139 · Court of First Instance, Hong Kong · Lam J (M H Lam J) · 23 February 2011 ·Source
Rules of the High Court (Cap. 4A), Appendix D, Code of conduct for expert witnesses
RHC (Cap. 4A) App D · subsidiary legislation ·Source
The Technology and Construction Court Guide, Fourth Edition 2026 (published 1 July 2026)
14.2 Permission always required; scope limited to what is necessary; costs estimates and issue-limited permission (CPR 35.4).
14.5 Meetings of experts: purposes listed; lawyers must not attend save exceptionally with permission and must not dictate what experts say; meet before and after reports.
14.6 Joint statement is 'a critical document'; experts may share drafts with lawyers for information only; lawyers must not negotiate, draft or revise it; serious concerns go first to the other side's lawyers, then to the court.
14.7 Reports independent and unbiased; parties identify issues, expert decides content; spreadsheets disclosed in native format; primary-fact evidence from an expert goes in a factual witness statement.
14.8 Presentation: summary at start of evidence, sequencing options, concurrent evidence ('hot-tubbing'), pre-trial tutorial.
1.6 Use of AI by legal representatives: personal responsibility; doubt about disclosure resolved in favour of disclosure; verify AI-assisted research and citations.
IBA Rules on the Taking of Evidence in International Arbitration
IBA Rules on the Taking of Evidence in International Arbitration (adopted by resolution of the IBA Council, 17 December 2020) ·Source
Commentary on the revised text of the 2020 IBA Rules on the Taking of Evidence in International Arbitration
IBA Task Force, Commentary on the revised text of the 2020 IBA Rules on the Taking of Evidence in International Arbitration (January 2021) ·Source
CIArb Protocol for the Use of Party-Appointed Expert Witnesses in International Arbitration
Chartered Institute of Arbitrators, Protocol for the Use of Party-Appointed Expert Witnesses in International Arbitration (September 2007), as reproduced in Annex I to the CIArb International Arbitration Practice Guideline: Party-appointed and Tribunal-appointed Expert Witnesses (2015) ·Source
A survey of 419 arbitrators, experts and counsel. The Report says its findings are perceptions, not measurements, and that in-house counsel responses were limited.
Report on Party-Appointed Expert Witnesses in International Arbitration: Effectiveness and Best Practice
Chartered Institute of Arbitrators, Report on Party-Appointed Expert Witnesses in International Arbitration: Effectiveness and Best Practice (V1, July 2026; published 9 July 2026) ·Source
SCL(S) Protocol for the Use of Experts' Joint Statements in Arbitration (1st edition)
Society of Construction Law (Singapore), Protocol for the Use of Experts' Joint Statements in Arbitration (1st edition, January 2026) ·Source
In force from 30 November 2026, three weeks after the webinar. The fourth edition applies until then.
RICS professional standard: Surveyors acting as expert witnesses (Global, 5th edition)
RICS, Surveyors acting as expert witnesses (professional standard, Global 5th edition, July 2026; effective 30 November 2026) ·Source
Instruct the expert in writing, with a list of the issues, and expect the tribunal to read the instructions. Under the IBA Rules the report describes them (art 5.2(b)); under the CIArb Protocol they are not privileged (art 5.1).
Give both experts the same material, including the documents that cut against the case (Kennedy v Cordia [57]; ICI v MMT [237]).
Settle the timetable with the expert before it is fixed. In the CIArb survey only 44% of experts said they are given enough time, and 60% wanted a say when the timetable is set.
If the expert's view changes, say so to the other side at once, through the lawyers (Guntrip v Cheney Coaches [17], [21]; the sixth of the Ikarian Reefer duties).
Keep counsel out of the joint statement. CIArb's 2026 Report has model wording for a procedural order, and the SCL (Singapore) Protocol has a declaration that the expert was not instructed to avoid agreement.
The CIArb Report does not ask for counsel to be shut out of the expert's work. It says that nothing in it suggests counsel should be excluded from engaging the expert, or that experts should operate independently of legal instruction (para 5.1.12).
Being paid does not defeat independence. The IBA Commentary says that receiving payment as an expert does not preclude independence, and that art 5.2(c) is meant to stress independent evaluation rather than to exclude experts with some connection to the case. The CIArb Protocol says the same of reasonable fees (art 4.2).
Most experts in the CIArb survey do not see over-instruction as a common problem: 73% said it happens never or not often. Whether that is the truth or a blind spot is one of the questions for the panel.