by Mark Henderson and Rowena Moffatt of Doughty Street Chambers
and Alison Pickup and Monika Nollet of Asylum Aid
~ Revised 2023 Edition ~
Objecting to inappropriate cross-examination
Examples of potentially objectionable cross-examination:
Not putting alleged inconsistent statements or putting them out of context
Putting the Home Office interview notes as if they have been accepted by the appellant
The discrepancy which is not a discrepancy
Criticising a 'failure' to provide information which had not previously been requested
Raising new issues without notice
Questions to which the witness cannot be expected to know the answer
HOPO giving evidence under the guise of cross-examination
Commenting on evidence instead of asking questions
Breaching another asylum seeker's confidentiality
Cross-examination of other factual witnesses
36.1 If you call your client, the HOPO is entitled to cross-examine her. (See chapter 30 for whether you should call her).
36.2 Since witness statements are required as evidence in chief, most of your client's oral evidence will normally be spent dealing with cross-examination. That is therefore the main opportunity that your client has to communicate directly with the Tribunal and the main opportunity for the Tribunal to assess her as a witness. One of your most important roles as advocate is to try to ensure that cross-examination is as fair as possible and gives her a reasonable opportunity to answer the allegations against her.
36.3 Law students are taught that the first rule of cross-examination is to put your case to the witness. HOPOs, apparently, are not. It is common to sit through a long and rambling cross-examination of questionable relevance, only to find that the most contentious allegation made in the HOPO's closing submission is the one that he did not find the time to put to the witness. It may be (indeed one might like to think) that the HOPO on occasion feels embarrassed about putting the more offensive parts of his case to the appellant, for example that she fabricated rape. However, that only renders it more offensive when he raises the allegation in closing without giving her the opportunity to respond to it in evidence.
36.4 In Vellupillai (00/TH/01468), the Tribunal held that:
It is fundamental ... in our adversarial system of justice that adverse matters or potentially adverse matters are put to a witness. We do not say that each and every aspect of an Appellant's evidence ought to be cross-examined but the purpose of cross-examination is to clarify, expand or undermine a witnesses' evidence. A cross-examiner is entitled to accept evidence as true and not cross-examine on it but the cross-examiner should always take care to ensure that key aspects of the evidence in chief which are not accepted are challenged. That is the whole purpose of cross-examination.
36.5 In Ezzi v SSHD (G0003A), it said that:
If the cross-examiner does not accept the evidence given in chief, or considers that it is not truthful, any contrary proposition which the cross-examiner intends to make in submissions should be put to the witness in order to elicit his response thereto. If that is not done, the evidence in chief of the witness has not been challenged nor tested. The Tribunal is thereby denied the opportunity to have matters fully explored and the Tribunal may be left in some doubt as to where the truth may lie. Furthermore, while submissions made in respect of key matters which have not been raised or challenged in cross-examination may not be incompetent, they cannot have the forcefulness of submissions in respect of matters which have been addressed during the hearing of evidence. The proceedings must be conducted in a manner which is fair to both sides.
35.5A In RR (Challenging evidence) Sri Lanka  UKUT 274 (IAC), the Tribunal was considering expert evidence which included evidence that the appellant had scars which were indicative of cigarette burns. It noted that the respondent had not suggested either in cross-examination or submissions that those cigarette burns were caused in any way other than as described by the appellant (although there was a general challenge to his credibility). The Tribunal held that "In the absence of any evidence tending to suggest a different mechanism we do not see how we can fairly reject the appellant's evidence about their cause when no alternative mechanism was put to him and he was not cross-examined on the basis that he was making up his entire case" (para 156). The headnote reads:
3. If the appellant or expert chooses to give oral evidence then the respondent's cross examination should fearlessly and clearly include the suggesting to the appellant or expert that, for example, an injury was not caused in the way alleged by the appellant but by a different mechanism.
4. If the respondent does not put its case clearly it may well be very difficult for the Tribunal to decide against an appellant who has not been given an opportunity to deal with the respondent's concern.
5. If a party has no basis for challenging evidence so that a challenge to the evidence would appear to be abusive or foolish then that party must think very carefully before making the challenge. It will probably be fairer to abandon the point.
36.6 Much cross-examination tends to traverse the same ground that has already been covered in the asylum interview, statement, or evidence in chief – apparently in the hope that an inconsistency can be elicited. The HOPO may seek confirmation of matters which have never been in dispute but which the HOPO believes assist his case, e.g. that she was never convicted of an offence. You should warn the witness that those sorts of questions will arise. Explanations may also be sought for the actions of the appellant (e.g. 'Why did you not leave the country earlier?'), or third parties (e.g. 'Why did the police not arrest you?'). Less frequently, the witness will be asked to comment on an allegation from the HOPO, usually that some part of the account is implausible.
36.7 This is one of your key roles at the hearing. It is imperative to concentrate on each question as it is asked so that you can object promptly where justified.
36.8 You should normally object to cross-examination if you consider the question is improper, unfair, irrelevant, confusing, misleading, based on a misunderstanding of the facts, or the HOPO is adopting a hectoring approach. Some representatives consider that a confident, articulate, sophisticated client can be left to deal with improper or confusing questions, effectively making her own objections. Others consider that regardless of the client's ability to deal with improper questions, part of the representative's duty is to do his best to ensure that proceedings are conducted fairly.
36.9 While you should not come across as overprotective of your client, do not decide to let an improper question pass unless you are very sure of your reasons. The fact that the Tribunal has over-ruled previous objections does not mean you should stop putting legitimate objections on record. It will be more difficult to challenge the fairness of cross-examination on appeal if you did not object at the time. Even if the objection is over-ruled, the HOPO will sometimes rephrase the question in a less objectionable way, and may at least think more carefully about how he puts future questions. Note, however, that the Upper Tribunal in Elais (fairness and extended family members)  UKUT 00300 (IAC) observed that 'cross examination should be facilitated without undue interruption' in order to conduct a fair hearing.
36.10 The risk of inappropriate cross-examination causing unfairness is much greater when vulnerable witnesses unused to formal proceedings are giving evidence through interpreters. Where an English speaking witness gives evidence in ordinary proceedings, he will be shown material documents during cross-examination and permitted to read alleged inconsistent statements and see the context in which they were made. Reviewing the relevant document is obviously useless to a non-English speaking witness. It is therefore critical that the cross-examiner is scrupulously fair in ensuring that any relevant document forming the basis of cross-examination is properly described and quoted before the witness is challenged on it.
36.11 Some of the examples below apply particularly to cross-examination of the appellant, but the same principles apply to cross-examination of other witnesses.
36.12 Questions based on mistakes as to dates and the sequence of events are common. You should point out the HOPO's mistake before the witness has the opportunity to respond to the question.
36.13 If he refers to evidence in the papers which you do not recognise, ask for him to give the bundle page reference before the question is translated. The HOPO may introduce a question by making an assertion about the 'objective evidence' before the court, only for it to transpire that he is referring simply to a Home Office document. The witness should not be misled about the nature of the evidence to which she is being asked to respond.
36.14 Also check that the HOPO is reading from the interview notes correctly. If there is no typed transcript of interview records, check this for sense. Mistakes in deciphering the handwriting may change the meaning of the note the HOPO is reading.
36.15 If the HOPO is going to ask a witness about something she is claimed to have said in a previous statement or interview, then the relevant passage should be read together with any further material necessary to put the passage in context. Particularly if the statement is being put as an alleged inconsistency, the HOPO should not be permitted to paraphrase it. If you feel that the extract read out by the HOPO is insufficient to enable the witness to understand the context, explain why the witness ought to be referred to additional passages before she answers the question.
36.16 Object if the HOPO appears to misrepresent your client's statements. For example the Home Office interview record may contain the following exchange:
Q: What was the date of the detention you have just told me about?
A: I cannot remember, it was during the summer of 1988.
Q: Please can you be more specific? I want to know the date.
A: I think it may have been June 1988.
36.17 The cross-examination may then be conducted as follows:
Q: During which month were you detained in 1988?
A: I think it might have been July.
Q: At your asylum interview you said your detention was in June but now you say July. How do you explain this discrepancy?
Objection: Point out that your client's answer at interview has been misrepresented, and ask the HOPO to read the full exchange before putting it to the appellant.
36.18 The HOPO may also fail to explain the circumstances in which the appellant is alleged to have made the inconsistent statement. There may be notes of one or more Home Office interviews before the court, plus additional written statements, but the HOPO may simply ask the witness:
So why did you say to the Home Office that you had no problems until 1990?
Objection: The appellant cannot simply be shown the document as can an English speaking witness. The witness is entitled to know when and where she is alleged to have made the statement. The HOPO should therefore provide the date and nature of the interview, or the date of the statement and by whom it was submitted (e.g. by present or previous representatives).
36.19 Given the delays that can occur, the HOPO may be putting statements to the appellant that she is alleged to have made months or years previously. Before asking 'Why did you say that?', it will usually be appropriate to ascertain whether the witness recalls saying it and/or accepts that she said it.
36.20 Home Office interviewers now refuse to read back their notes to the claimant at the end of the asylum interview in order to check their accuracy. The Home Office previously claimed that 'The read back is an essential part of the interview' (Still No Reason at All, Asylum Aid, 1999). The HOPO's tactic in cross-examination used to be to confirm that a read back was conducted and the record agreed by the appellant. Since the Home Office refuses to conduct this procedure which it previously accepted was 'essential' to establish the accuracy of the interview record, the HOPO should not put the interviewing officer's record to the appellant as if she has already approved it. As explained in chapter 1, the standard interview record used to contain a declaration to be signed by the appellant to confirm receipt of the interview record and "approval" of its contents (see para 1.25C). But it would rarely have been the case that there was any kind of read-back before that declaration was signed and your witness statement should have explained this. You should object to any suggestion by the HOPO that this declaration has the effect that the interview record should be treated as being adopted by the appellant.
36.21 Sometimes, the HOPO will refer to a part of the interview note which the appellant's statement already explains is inaccurate. It is open to the HOPO to dispute what was said at interview. But he should not suggest that evidence is undisputed when that is not the case. Although the interview record now contains a declaration signed by the interviewing officer as to its accuracy (para 1.25B), the interviewer will not normally be called to give evidence. If your client disputes the record, the Tribunal should normally be invited to prefer her oral evidence to a generic 'declaration' from an official who has made no witness statement in the appeal and has not been made available for cross-examination.
36.21A In MB (admissible evidence; interview records) Iran  UKUT 00119 (IAC), the Tribunal pointed out that issues about the accuracy or the fairness of the interview record may affect the weight to be attached to its contents, particularly where the interview was not tape-recorded and there was no contemporaneous read back. However, the fact that its contents are disputed and that it was obtained in an unfair manner does not mean that it is inadmissible, although if a dispute becomes apparent for the first time during questioning, it may well be necessary to adjourn to check the recording of the interview.
36.22 HOPOs will often ask a witness to explain a 'discrepancy' when there is no discrepancy to explain:
Today you said that your father had written to you saying that your brother had been arrested, but you said in your interview that you have had no contact with your family since leaving your country. How do you explain this discrepancy?
Objection: the interview was long before the hearing. It may be that the appellant had not heard from her family at the date of the interview but has heard from them since. The HOPO has assumed a discrepancy which has not been established. He should at least be required to give the date on which the appellant had said that she had not heard from her family.
36.23 Another example is:
You say in your statement that you have been an activist since 1998, but in your asylum interview you said you sympathised with the organisation in 1996. Why are you telling a different story now from that which you told in your interview?
Objection: The two are not inconsistent. She need not be an activist in order to be a sympathiser. This is a point that might be left to the witness if evidence were being given in English. But you cannot rely on the nuances surviving interpretation. Indeed, having been told by the HOPO that there is a discrepancy because she gave conflicting dates for the same activity, the court interpreter may assume that it is appropriate to use the same word from the appellant's language to describe the activity when translating each statement.
36.24 The HOPO might say:
You've told us today that you were ill when you passed through Russia on your way to claim asylum in the United Kingdom, but you did not mention this during your asylum interview. Why have you just remembered now that you were ill in Russia?
Objection: She was never asked during her asylum interview whether she was ill in Russia. The asylum interview record is the record of an interview, not a complete record of the appellant's life.
36.25 Another example is:
You have said today that you were tortured while you were detained, but you did not say you were tortured when asked about your detention during the asylum interview.
Objection: The appellant was asked when she was detained at the interview and she answered. She was not asked how she was treated during her detention, and the interviewer may have moved straight onto a new topic (see further para 1.23). If the witness had a complete recollection in her head of an interview conducted some time ago, she could point this out herself. But it is unfair to expect this degree of recollection. If she has no clear recollection then she may assume that the HOPO could not be criticising her in this manner unless she had been asked about her treatment during detention. At the very least, the HOPO should be asked to read the questions and answers which addressed this particular detention.
36.26 The HOPO may also allege that failure to repeat during the asylum interview information which was given in a previous SEF or statement represents a discrepancy:
In your SEF, you said you had been subjected to torture yet there is no mention of this in your subsequent interview.
36.27 As indicated at para 1.19, this is a particularly dubious tactic when one considers the guidance in the API that where a statement has been submitted, "an interview should focus on gaps in evidence; areas lacking in clarity; issues of plausibility and other areas of doubt rather than simply repeating the contents of the statement verbatim." If such an allegation was included in the refusal letter, you should have objected in your skeleton argument. If the HOPO has not taken issue with the submission contained in your skeleton, point that out when you object during cross-examination.
36.29 If you object to the witness being told there is a discrepancy in her statement when she simply did not answer a question that she was not asked, the HOPO will sometimes claim that a question at the end of the interview enquiring whether there is anything to add is sufficient for these purposes. The asylum interview may consist of a long list of questions over many hours. The asylum seeker will normally have been advised by her representative to restrict herself to answering the questions she is asked. The very detail of the interview may imply that the opportunity to add anything at the end refers to the questions which have been asked in the interview.
It might be different if, at the end of the interview, the interviewer were to say: 'I have finished my questions but you are now required to make a statement before you leave describing all details of your claim that I have not asked you about: a failure to do so will be held against you when such details are provided later.' But that, of course, is not what the asylum seeker is told.
36.30 A similar issue may arise over written witness statements. These are usually drafted by a representative on the basis of one or more interviews with the appellant. As discussed in chapter 13 the methodology and quality varies drastically. The HOPO may question the appellant on the premise that she drafted the witness statement herself. As far as the appellant is concerned, it would simply have constituted another interview where she answered the questions that were put. The statement may not even have been properly checked prior to submission. The reason why a point is not contained in her statement is most probably that her representative did not ask her about it. However, the HOPO may put to the appellant that 'You had the opportunity to say whatever you chose in your statement.' To make such a claim, the HOPO would first have to establish how the statement was taken. As indicated at para 13.15, the HOPO sometimes approaches this point with a unique unwillingness to contemplate a representative following anything other than best practice.
36.31 Your client may have started her statement with her early life and early problems, but made clear that it is not the basis of her present claim. The HOPO may fail to understand this and start asking detailed questions about events which occurred decades ago. Apart from irrelevant questions being inappropriate in principle, it will save valuable court time if you point out to the HOPO that these matters do not form the basis of the present claim. 'It is no part of (the advocate's) duty to embark on lengthy cross-examination on matters which are not really in issue' (Simmonds  1 QB 685). In R v Maynard (1979) 69 Cr. App. R. 309, the Court of Appeal noted that even though counsel may be allowed more latitude in a criminal case, the judge nevertheless had a 'duty to curb irrelevancy' and reiterated its earlier dictum in R v Kalia (1974) 60 Cr. App. R 200 to the effect that:
The trial judge can and should do his utmost to restrain unnecessary, prolonged cross-examination, and this Court will unhesitatingly support him when he does...
36.32 Sometimes, the explanation for a line of cross-examination which is irrelevant to the Home Office's decision will be that the HOPO is planning on raising new reasons for refusal which did not form part of the original decision. If this is the response to your query about the question's relevance, you will normally object. While it is unsatisfactory to raise a new issue at the start of the hearing, it is even more so to raise it for the first time during cross-examination when the absence of prior notice has precluded you from taking instructions. You will be in a particularly strong position if you have sought details of the Home Office's case (chapter 9).
36.33 If the Home Office is not prevented from taking a new point at the hearing which it declined to take in the decision, it may well be unfair for that to be done without offering you an adjournment in order to take instructions and if necessary submit further evidence to deal with it. But given the general undesirability of adjournment, that should militate against the Home Office being permitted to take the new point at all – particularly if the HOPO can give no good reason why it was not raised in the decision or at least prior to the commencement of the hearing.
36.34 HOPOs repeatedly ask witnesses to explain the actions of third parties, e.g. 'Why did the police not search for you?' Your client is not the police. If the HOPO wants to 'know' why they did not search for her (assuming they did not), then it would be appropriate to ask the police. The appellant should not be asked questions which demand an explanation for the actions of others without establishing whether she is in a position to know. He should first establish if the appellant actually knows that the police did not search for her before enquiring 'Do you know why not?' If the question does not allow for the possibility that she does not know, an inexperienced witness may assume that she is required to provide the information and offer what is effectively a guess. If that guess is along the lines that the police did not have enough evidence or information, the HOPO may seize on this as confirmation that the appellant is at no risk. The dangers involved in this style of questioning are discussed further at para 12.24.
36.35 The HOPO may make more ambitious assumptions about the appellant's insight. In one case, described in a report by Asylum Aid, 'Still No Reason at All', the appellant had been shot in the leg whilst fleeing Islamic gunmen. The HOPO's cross-examination was:
If they had really wanted to get you, why did they shoot you in the leg, and not the head?
The adjudicator over-ruled the question.
36.35A Another example is given by the Upper Tribunal in Wagner (advocates' conduct – fair hearing)  UKUT 655 (IAC) which noted that 'it was plainly inappropriate to ask the Appellant or his spouse why the medical expert who had compiled the report in question had not detailed the relevant medication.'
36.36 The HOPO may use cross-examination to assert facts which are not even referred to in the refusal letter, never mind supported by evidence. If the HOPO wishes to lead evidence of those facts, then he may do so, whether documentary or oral, and, if oral, you will have the right to cross-examine whoever he calls. On at least one occasion when the HOPO was prevented from giving evidence during cross-examination, the HOPO responded by calling himself as a witness. The judge accepted the HOPO as a credible witness and dismissed the appeal. The Tribunal allowed the appeal on the basis that the adjudicator erred in permitting a representative to give evidence (Aitsaid (11391)).
36.37 Examples of potential 'questions' include:
You say you were stopped by the Special Branch but that's not true because the Special Branch only operate in the capital.
l suggest that there is no way that you would have been able to bribe your way through that airport given the security in place.
Objection: Ask the HOPO if he is going to lead evidence about the areas in which Special Branch operates or on what security is in place at the particular airport. If he is not going to lead evidence to establish it, then he should not be asserting the 'fact'. Cross-examination is the wrong place for such assertions in any event. 'An advocate must not in the course of cross-examination state matters of fact or opinion... ' (Archbold, 2003, para 8–116).
36.37A In HK (Interviewer as advocate: unfair?) Ethiopia  UKAIT 00081, the Tribunal considered the position where the Home Office official who conducted the asylum interview also presents the appeal, which may arise either through chance or because (as was the aim with the New Asylum Model) the case owner has done both. The main concern was that a challenge to the conduct of the interview or the accuracy of the interview record may require the interviewer to give evidence.
36.37B The Tribunal said that
33... In the Tribunal's judgment it will be clear in the majority of asylum claims that the Interviewing Officer will neither be required to nor needed to give evidence about the contents of the interview or what happened during the interview process itself. In those circumstances we see no objection to the Interviewing Officer acting as Presenting Officer. There is no common law prohibition on advocates acting as witnesses and the statutory position of Home Office Presenting Officers contains no such prohibition either.
36.37C It gave the following guidance:
37. There may be rare cases in which it is alleged that the interview has been conducted in a wholly inappropriate manner with allegations of hectoring, bullying or the like. Such an allegation should be made promptly by anyone asserting such conduct. It will be for the respondent to decide if the allegation needs to be dealt with by formal evidence. As a party he is responsible for deciding what matters are put on his behalf before the Tribunal.
38. Challenges of this sort are likely to be personal attacks on the integrity of the interviewer and what took place. Where the respondent accepts that the allegation will need to be dealt with by evidence from the Interviewing Officer it will be wise for that officer not to appear as an advocate. Indeed it might be unfair for such an interviewer to represent. It is foreseeable, for instance, that the tendency for animosity could be so strong that the immigration judge might well have to intervene and stop the hearing or insist that the respondent was separately represented or stop points being put to a witness.
39. There may be cases where similar allegations are raised for the first time at a Tribunal hearing. It is likely to be a matter for comment that the issue was not raised previously. But it will be for the Judge to decide how to proceed. Applications for adjournments at what will be a very late stage will need to be considered having regard to the overriding objective. It may be appropriate to suggest to the Presenting Officer that he or she might wish to give evidence on the issue rather than deal with the position solely in submissions. Whether such evidence is given or not will be the decision of the interviewer/advocate. But the judge must control the proceedings.
36.38 The HOPO may make derogatory comments in response to the witness' answer such as 'I find that completely implausible.' If the HOPO has any comment to make on the evidence, then he should make it in his closing submissions. '[C]ross-examination must not be used for making comments, which should be confined to speeches' (Archbold, ibid). The Upper Tribunal in Wagner (advocates' conduct – fair hearing)  UKUT 655 (IAC) also confirms this basic principle of cross-examination: '…mere comments by representatives under the guise of questioning of a party or witness are not appropriate. They are forbidden by the most elementary principles and rules of advocacy.'
36.39 By commenting, he may also be straying into giving evidence. If he alleges that something is likely, what is his basis for doing so: his knowledge or experience of the country of origin? If he wants to put to the witness that something is implausible then he should do so. A confident English speaking witness might understand that he is entitled to respond to such a comment. An asylum seeker may not do so and, worse, may regard it as some sort of conclusion on her evidence which may adversely affect her future evidence.
36.40 The HOPO may criticise the witness for not answering the question when she has plainly done so to the best of her ability. This is another unfair method of discomforting her. He may similarly demand that she answer yes or no to a question when the appellant is trying to explain that it is not that simple. You should also object if the HOPO interrupts an answer, particularly before it has been fully translated.
36.40A In Wagner (advocates' conduct – fair hearing)  UKUT 655 (IAC) the Upper Tribunal criticised 'inappropriate' and 'improper' cross examination by the HOPO and said: 'the role of the advocate does not properly encompass either aggressive questioning or confrontation: where either occurs, a boundary has been crossed and the presiding Judge should intervene.'
36.41 HOPOs have in the past made assertions in cross-examination that the witness' evidence regarding a particular event is inconsistent with that given in the claim of another asylum seeker (whether relative, friend, or acquaintance) who is not party to the appeal or represented at the hearing. That may well be contrary to the Home Office's own undertaking of confidentiality and with the policy set out in the API on Dependents (see para 1.27). You should object immediately if it appears that the HOPO is breaching that undertaking.
36.42 Communication between you (or any other representative) and your client concerning the preparation of your appeal is privileged. You may object to any question which would require the appellant to reveal such information. Communication between either you or your client and any expert may also be privileged (though see para 23.6 concerning the duty to disclose an expert's instructions). In R (oaa SSHD) v First-tier Tribunal (IAC) (Litigation Privilege; First-tier Tribunal)  UKUT 00243 (IAC) the Tribunal said:
Litigation privilege attaches to communications between a client and/or his lawyer and third parties for the purpose of litigation. It entitles the privileged party not to disclose information even if it is relevant to the issues to be determined in a court or tribunal. Proceedings in the First-tier Tribunal are sufficiently adversarial in nature to give rise to litigation privilege. The fact that human rights issues are in play does not mean litigation privilege has to be balanced against those issues
36.43 However, it is important to keep in mind that it will not always be in your client's interests to object to the disclosure of privileged information. It may in fact be necessary, for example, to explain why a witness statement is unsatisfactory.
36.44 The simplest, yet one of the most important objections you must make is to unclear, convoluted and ambiguous questions. If you are unsure what the HOPO is getting at, then there is little prospect that the witness will be able to guess correctly. Even if the question is tolerably clear in English, it may be incomprehensible by the time it has been translated. You may also object if a question in cross-examination is difficult to interpret, e.g. because it involves a double-negative (para 34.26).
36.45 The HOPO will have had advance notice of the evidence of other factual witnesses through the service of their witness statements. The purpose of providing these statements in advance is to give the Home Office the opportunity to consider its position. If the HOPO neither indicates in advance that the evidence is disputed nor challenges the witness in cross-examination, fairness should not permit him to challenge it in closing submissions.
36.46 As indicated in chapter 15, the HOPO is quite likely to ask the witness questions about the appellant's evidence in the hope of eliciting an inconsistency. The witness should be warned not to guess at answers and that it is perfectly alright to explain that he does not know. If the HOPO persists, you should object.
36.47 Cross-examination of expert witnesses is dealt with in chapter 25.