Advocacy & Experts

The aim of the advocate is to win at trial within the rules of law, evidence, and professional ethics. ‘The means of winning is by being persuasive… Rightly or wrongly, adversarial advocacy is not really an enquiry into the truth. Perhaps the adversarial system should be about finding out what really happened. But it isn’t. Instead it creates a polite contest. The contest is this: while a judge will seek out the truth as best they can, the advocates use their skill to test the evidence, and to control the way the evidence emerges, and then comment in closing on whether a case has been proved to the necessary standard of proof.’ (Morley).

‘A trial is not an exercise designed to discover the truth. The rules of evidence are mainly designed to exclude. They often operate to prevent the evidence actually presented from showing the truth of the matter at all … The Judge is not an investigator but more like an umpire … What we are doing as advocates is trying to get the fact finder to arrive at an opinion, an opinion in our favour … our objective at trial is not the ultimate truth but an opinion in our favour.’ [Evans].

‘The task of the advocate is to be argumentative, inquisitive, indignant or apologetic – as the occasion demands – and always persuasive on behalf of the person who pays for his voice …when making submissions to a judge … or cross-examining hostile witnesses, the advocate is required to entice, to flatter, [and within the boundaries of what is ethically permissible to ridicule and] to insult, all in order to advance the cause for which he is instructed. The professional function of the advocate is, essentially, one of supreme, even sublime indifference to much of what matters in life. He must advance one point of view irrespective of its inadequacies. He must belittle other interests, whatever their merits … It is not for counsel appearing in court to express equivocation, to recognize ambiguity or to doubt instructions. His client is right and his opponent is wrong. The wider consequences can be left to the judge. The fundamental role of the advocate is not to enlarge the intellectual horizon. His task is to seduce, to seize the mind for a predetermined end, not to explore paths to truth.’ [Advocates].

At trial, the strategic objectives of the advocate therefore include:

(i) persuading the judge to rule in favour of the lay client through the admission and convincing presentation of expert evidence (which includes anticipating attacks upon the credibility of the expert and the value of his evidence);

(ii) the exclusion of expert evidence relied upon by the other party; and

(iii) undermining the credibility of the opponent’s expert, and the value of his evidence, to minimize the weight that the judge will attach to that expert’s opinions and conclusions, i.e. to neutralise its effect in the mind of the judge, e.g. by getting the expert to agree to a point which can be referred to in closing in order to submit that his evidence is abstract and incomplete, and therefore that the evidence of witnesses of fact who knew and or met the testator should carry equal if not greater weight, or to submit that the expert expressed no opinion about the possibility that a disposition made by a deceased testator while prima facie eccentric, was not necessarily irrational, and was in fact in character, i.e. to cast doubt about the probative value of the expert evidence and to add weight to an alternative case theory/narrative.

When examining his own expert witness the advocate’s aims include:

(i) ensuring that the judge understand the expert’s evidence;

(ii) persuading the judge of points essential to the case; and

(iii) anticipating the other side’s cross-examination and fortifying against that assault.

The expert is obliged to state his qualifications in his report (PD 35, paragraph 3.2(1)). The usual practice at trial is for the judge to be referred to the relevant page in the report and for the advocate to then move on to the substance of the expert’s evidence. ‘In almost every civil case the expert will have written a report before the trial which will have been disclosed to the other parties pursuant to a direction of the court. This report should have been pre-read by the judge and examination-in-chief is usually relatively brief consisting of the advocate highlighting the important sections of the report and asking the expert to amplify or clarify ambiguities in the report and, sometimes, to comment on issues raised by the other side’s expert (albeit that this has usually been done in the expert’s joint statement) and/or issues that have arisen since he wrote the report. The bulk of the expert’s time in the witness box is usually taken up with cross-examination. In many civil cases (in particular those involving a single joint expert all of the expert evidence is given by report alone and, thus examination-in-chief does not arise.’ [Expert Evidence, paragraph 8-012].

The opinion of an expert, however correct, is of no use to the court unless it is clearly formed by inference from facts which have been or are to be proved in evidence. The expert must always, in expressing an opinion, indicate which facts he relies upon. Counsel calling an expert should therefore in examination in-chief, ask his witness to state the facts upon which his opinion is based. It is wrong to leave the other side to elicit the facts by cross-examination. ‘Unless a witness states in his evidence in chief the grounds and reasoning that have led to the opinion, the opinion is valueless.’ Cadbury Schweppes v Durrell Lea [2007].

Once the expert’s opinion has been stated, immediately provide the underlying theory. The theory should furnish the nexus between the expert’s conclusion and the data used to support the conclusion. In other words the examination should follow this pattern:

(i) here is my opinion;

(ii) here are the principles that support my opinion; and

(iii) here is what I did to reach my final conclusion.

Having stated and supported his theory choice, the expert can then specify the nature of his investigations and tests. It is not necessary to explain or outline every hypothesis used by your expert, but the more important assumptions should be noted and supported. The examination in chief of an expert should conclude with a powerful restatement of his most important conclusions. Many complex ideas can be made understandable with examples, analogies, or metaphors. Expert witnesses should be encouraged to clarify their testimony through the use of such imagery. (Lubet pages 224 to 232).

Just as a party must in cross-examination challenge evidence of fact given in chief by a lay witness which is not accepted, so the opinions of an expert must be challenged if they are to be disputed. The purpose of cross-examination is to:

(i) elicit support for your own case, and to weaken your opponent’s case; and

(ii) put your client’s case (including as to the fact or content of documents) to the witness to afford the witness the opportunity to respond to it.

‘Effective cross-examination of an expert is no different than of any other witness: you must have a sound analytical approach to the witness so that you can determine whether to cross-examine and, if so, how to organize and execute the cross-examination to carry out realistically attainable goals. This approach involves the following basic considerations.

a. Should you cross-examine? Not every witness needs to be cross examined. If the expert has not hurt you, or if you have no effective points to make, or your own experts have been more persuasive, consider not cross-examining.

b. How should the cross-examination be organized? All cross-examinations have two possible basic purposes: eliciting favourable testimony, and conducting a destructive cross. Eliciting favourable testimony ordinarily comes before a destructive cross. If the expert has substantially helped you by agreeing to helpful facts, consider not attempting a destructive cross at all, although you have destructive ammunition.

c. Effective cross-examinations have a structure that starts strong, and keeps it simple. They maintain control over the witness by asking simple, leading questions and stop when the point is made.

d. What favourable information can you elicit? Did the witness say things on direct that you can have her repeat on cross? Can the witness admit facts not yet mentioned that support your case? What must the witness admit that helps?

e. What discrediting or destructive cross-examination can you do? Are the witness’s perception, memory, or communication skills vulnerable? Can the witness be impeached? Can you expose the witness’s bias, interest, or motive? Has she made prior inconsistent statements? Can the witness be impeached by a treatise? A good approach to any cross-examination is to ask yourself: what will I say about this witness in closing arguments? Planning the cross-examination is then a matter of determining what facts you can realistically make the witness admit during cross-examination that support your planned closing argument.’ (Mauet, page 365).

‘In general, if wishing to contest the opinion of an expert being called by our opponent, we can either contest the factual basis of the opinion, or we can contest the opinion itself. If the factual basis of the opinion is disputed, then we should be able to get the witness to agree in cross-examination that if the facts were as we contend, then his or her opinion would be different. If it is the opinion which we are contesting, on the other hand, then we will probably need to call our own expert witness… There are six critical questions we can ask about experts:

1. Expertise questions: How credible is E as an expert source?

2. Field question: Is E an expert in the field that A is in?

3. Opinion question: What did E assert that implies A?

4. Trustworthiness question: Is E personally reliable as a source?

5. Consistency question: Is A consistent with what other experts assert?

6. Backup evidence question: Is E’s assertion based on evidence? …

The expert’s possession of special expertise or knowledge is obviously the main foundational fact for expert opinion evidence; but it is not sufficient to prove some expertise at large. The expert witness must also be shown to be an expert in the field to which the issue about which they have been called to give evidence belongs.’ [Palmer, page 148].

An expert may be:

(i) challenged as to credit in relation to his opinion as he may in respect of facts;

(ii) asked to justify or deny particular opinions expressed on other occasions (including evidence given in similar cases) to cast doubt upon the opinions he has expressed in the present case;

(iii) asked about his attitude to the parties, i.e. if it is suggested that he is biased; and

(iv) questioned about whether he is or was not in a physical or mental state to express a proper opinion.

When cross-examining an expert witness the advocate’s aims specifically include:

‘(a) limiting the witness’s apparent expertise. Narrow the extent of his or her expertise/experience by showing that it is not directly applicable to the case in question or, perhaps, by contrasting it to the experience of your expert;

(b) showing that the witness has had less involvement/contact with the case than your expert;

(c) showing your knowledge of the expert’s subject. Using your knowledge of the technical terms involved or the way in which any tests were carried out, the expert will be less inclined to avoid your questions. Contrast this approach with the way you may deal with an ordinary witness of fact by simplifying technical terms;

(d) inviting the witness to define technical terms and sometimes in highly complex matters it may be necessary to invite the expert to use common language;

(e) challenging his or her methods, for example showing that there were other tests that the expert could/should have carried out that might have produced a different result. Remember to check that the expert’s facts, calculations and methods do actually produce the results set out in his or her report and, if they do not, challenge the expert as this may undermine the confidence and credibility of the expert’s evidence;

(f) inviting the witness to agree with the propositions that form the basis of your expert’s opinion – he or she is unlikely to disagree with everything your expert says, and you should know from your own expert those areas that are in dispute. Remember to ‘put your case’ to the expert by inviting him or her to deal with your expert’s methods/opinions/conclusions;

(g) inviting the witness to agree that, in his or her field, legitimate differences of opinion frequently occur between qualified experts. This shows that the witness is not infallible and that his or her evidence is ‘opinion’ only; and

(h) using hypothetical facts to test the strength of the expert’s opinion. Testing whether a different interpretation of the same facts or a slight change in those facts would affect the expert’s opinion.’ [Advocacy, paragraph 22.7.1].

Paragraph 5 of PD 35 provides, ‘Cross-examination of experts on the contents of their instructions will not be allowed unless the court permits it (or unless the party who gave the instructions consents). Before it gives permission the court must be satisfied that there are reasonable grounds to consider that the statement in the report of the substance of the instructions is inaccurate or incomplete. If the court is so satisfied, it will allow the cross-examination where it appears to be in the interests of justice.’

Cross-examination of an expert witness is a hazardous undertaking. ‘A witness under cross-examination does not want to agree with you. He will fight tooth and nail to confound you. He will misunderstand your questions. He will provide evasive answers. He will try to use your questions as an excuse to repeat the deadly features in his testimony which destroy your case. Unlike TV, a witness has no script which must be followed. He will try everything to wriggle out from under your questions. Every question in cross-examination is an invitation to disaster. It is an opportunity for the witness to hammer you and your case. So your first thought is don’t do it. Always start from the point of view: if I can avoid it, I will.’ [Morley].

The advantage of a cross-examiner over even the most prepared witness is that only the cross-examiner knows which questions are going to be put next… 10 cardinal rules:

(i) Always put your case to a witness in so far as it is relevant to that person’s evidence. Failure to do so may damage your case and may result in the witness being recalled.

(ii) Keep your xx to what is absolutely necessary.

(iii) Leading questions are permissible and should be used. Put propositions to a witness. Don’t give them a chance to give equivocal answers. Listen carefully to what they have to say. If a witness avoids answering the question put it again until he/she does.

(iv) Do not ask multiple questions. Keep them short and keep a tight rein on the witness. You should be in charge.

(v) Permissible – forceful/insistent. Impermissible – hectoring/bullying. XX does not mean being cross. Never lose your temper with a witness.

(vi) Let the witness finish his/her answer, before proceeding to the next question. If a damaging answer has been given, pause before proceeding. Silence is golden. Let it sink in.

(vii) Watch the Judge’s pen. No matter how good the XX is, if the Judge cannot record it, it may be lost. On a long trial, try to get a daily transcript if possible, it is very helpful for closing speeches.

(viii) Never put questions on a false premise. It denudes the XX of its force and makes you look bad/ incompetent/unprepared. (ix) Never misrepresent a witness’s earlier answer. (x) Put questions, don’t make speeches/submissions. Don’t clutter the questions with comment – save that for closing.’ (Hochhauser).

The purpose of re-examination is to correct, clarify or expand matters arising out of cross-examination. No question may be asked in re-examination which does not arise out of cross-examination. The basic rule about re-examination is do not do it, i.e. ‘break glass in the event of emergency’.

For the Bibliography, see: Handout.pdf ( (from which the above is an extract).

See also:

The Advocate and the Expert in a Testamentary Capacity Claim – Layout 1 (

The Advocate and the Expert in the Court of Protection | Expert Witness Journal

Mediation in the Court of Protection | Carl’s Wealth Planning Blog