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Experts' Joint Statements: Key Medico-Legal Issues - Koch, HCH, Davies M & Laraway A

27/04/20. This is the twenty-eighth in a series of Case reports and Commentaries from Professor Koch and colleagues in Hugh Koch Associates and Birmingham City University. Legal Mind Case and Commentary.

Background: Christopher Sharp QC (St. John’s Chambers, Bristol) reviewed a series of recent cases which involved the preparation of Joint Statements. This excellent review raised a number of issues which are discussed here (Sharp C (2019) Part 35 and the Expert’s Joint Statement).

Key words: Joint statement; Expert Witnesses; Opinion; Communication; Microskills


a) Mayr and others v. CMS Cameron McKenna Nabarro Olswang LLP [2018] EWHC 3669 (Comm).

In this case one party’s expert did not fully commit to the spirit or process of the experts’ discussion and failed to address the pertinent issues. The court requires the experts in a joint discussion to be constructive, discuss the contents of respective reports and substantive issues, reaching agreement when they can, and setting out concisely where they cannot reach agreement and why.

b) BDW Trading Ltd v. Integral Geotechnique (Wales) Ltd [2018] EWHC 1915 (TCC)

The presiding judge held that is was inappropriate for experts to seek input from their client’s solicitors into the substantive content of the Joint Statement. The TCC guide (at 13.6.3) state that legal advisors may assist in identifying issues which the statement should address, however.

c) Saunders v. Central Manchester University Hospitals NHS Foundation [2018] EWHC 343.

The judge in this case was critical of a ‘War and Peace’ report – a 60-page Joint Statement – that in his view did nothing to ‘agree or narrow’ the issues. This indicated a failure to cooperate. What was needed was a succinct and clear summary of issues and the reasons for remaining disagreement.

d) Jones v. Kaney [2011] UKSC13

This now well-known case resulted in the Supreme Court abolishing expert witness immunity following the expert psychologist, Kaney, amending significantly her diagnosis as a result of the Joint Statement discussions and not communicating reasons for this to her instructing party. Her involvement in the Joint Statement process had been flawed.

e) Igloo Regeneration (General Partner) Ltd v. Powell Williams Partnership [2013] EWHC 1718 (TCC).

In this professional negligence case, there were many addendum reports exchanged and repetitive restatement of opinions, plus an excessive level of conflict between the experts. Their ability to precis and clarify was restricted.


From these cases and Sharp’s excellent review the following substantive issues emerge for the experts conducting a joint discussion:

1. The crucial importance of the two experts fully understanding their duties to the court and the relevant CPR rules pertaining to joint discussions.

2. The need to read and fully understand each other’s reports.

3. Their ability to precis and clarify their opinions and reduce issues to the key pertinent areas.

4. To maximise the level of logical agreement.

5. To only change their opinion in extremis on the basis of newly presented valid information (this does not mean ‘in the face of opposing expert’s assertiveness’!)

6. To explain carefully and fully why an opinion has been altered.

7. The search of evidential certainty, reliability and validity is crucial, and the main objective – formerly it used to feel as if the ‘adversarial battle’ was the key issue, not so. This search is illustrated in Figure 1 below:


Experts who embark on the Joint Statement process need to use highly logical and effective communication skills and be willing to consider a range of opinions and contributory factors. For example, in the context of psychological injury cases, the two experts would need to consider the following: -

1) PTSD-type symptomatology – the life-threatening nature of the index event and overall PTSD diagnosis could be interpreted differently.

2) Different time scale of interviews if the experts interviewed the claimant 1-2 years apart, and this inevitably would explain some differences in symptom self-report by the claimant, plus the passage of time had resulted in significant improvement, which in turn affected recall.

3) Diagnostic Agreement: The experts agreed on the diagnosis of a recognised psychological disorder attributable to the index accident, even though they may disagree about diagnostic label.

4) Pre-existing vulnerability: The experts may not agree on the existence of earlier predisposition to mood disturbance, or lack of active symptoms in the 12-month period prior to the index accident.

5) Duration: The experts may agree on a short duration with one expert opining a longer duration of symptoms.

6) The expert communication skills needed are illustrated in the micro skill hierarchy shown in figure 2 below.


The key practical factors that could adversely affect the case and effectiveness of conducting a joint opinion are: -

a. Personality and style of expert: Most experts who had been working for many years attested to their colleagues being easier to get on with and debate differing opinions. However, the communication style and personality of the other expert could still be a factor contributing to difficulty in producing a useful joint opinion.

b. Accessibility and efficiency of other experts: “Sometimes making contact with other experts was very difficult”. When responding to tight time constraints either imposed by the court, instructing solicitor or one’s own competing, often clinical, commitments, the ability to make easy, rapid and ‘one stop’ contact with the other expert makes life considerably easier, or adversely if absent, very difficult and time consuming.

c. As a result of discussion, a statement is prepared, agreed and signed by both experts at the conclusion of the discussion and copies provided to each party. This can involve several exchanges of email with minor amendments. The efficient internet-based contact is a key factor in completing the joint opinion within the required time limit.

A balance is always necessary to maintain between individual professional opinion (clinical and medico-legal) and increasing consistency on interpretation of evidence and multi-sourced data. The court requires that the appropriate range of opinions has been considered by both experts in their initial report and subsequently when they undertake the joint opinion direction.

Further areas of enquiry might usefully cover range of opinion (diagnostic, causation, or prognosis) within the key professions and structure of joint opinion with/without a provided initial agenda.

The Joint discussion is a crucial part of the medico-legal trail as shown in Figure 3 below. The Joint Statement is not a mandatory requirement, but the usual general directions PD 28 para 3.9(5) and PD 29 para 4.10 (6) direct that if Experts Reports are not agreed then a Joint Statement should be prepared in dealing with the requirements of CPR 35.12.


The Joint Statement process is unique to England and Wales, with occasional use in Northern Ireland and Scotland and it not used elsewhere. The Courts in the above jurisdictions lead the way in the use of Joint Statements in legal conflict resolution.


Prof. Hugh Koch, Mr Michael Davies and Dr Alec Laraway.

Prof. Hugh Koch is a visiting professor in Law and Psychology at Birmingham City University (

Mr Michael Davies is a Solicitor (non-practising) and Lecturer in Law at Birmingham City University

Dr Alec Laraway is a clinical psychologist with Hugh Koch Associates, Cheltenham, UK (


Koch, HCH. (2016) Legal Mind: Contemporary Issues in Psychological Injury and Law. Expert Witness Publications. Manchester.

Koch, HCH. (2018). From Therapist’s Chair to Courtroom: Understanding Tort Law Psychology. Expert Witness Publications. Manchester.

Koch, HCH., Nokling, K.E. and Nolan, L. (2020). Legal Mind Case & Commentary No.25: Giving a range of opinions on psychological cases: Independence, Objectivity and Impartiality of CPR Part 35 experts. PIBULJ. January 2020.

Koch, HCH., McFadyen K., Crowther-Green, H. and Milner, P. (2019). Legal Mind Case & Commentary No.24: Gestmin and Witness Evidence. PIBULJ. November 2019.

Koch, HCH., Browne, C. and Medley, A,. (2018) Legal Mind Case & Commentary No.19. Expert Opinion Change in Joint Statement. PIBULJ. October 2018.

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