opinion evidence Flashcards
(16 cards)
1
Q
introduction
A
- The general rule is that witnesses may only give evidence of facts, not opinions or inferences. However, exceptions exist.
- Expert witnesses may give opinion evidence on matters within their expertise, as they possess specialized knowledge that the fact-finder lacks.
- Non-expert opinion evidence may also be admissible where necessary, such as when fact and inference are inseparable, when the witness is better positioned than the fact-finder to draw the inference, or when it is simply practical to allow such evidence.
2
Q
General rule
A
- Witnesses are generally restricted to testifying about facts they have directly observed, rather than offering inferences or conclusions. This rule stems from the principle that it is the role of the tribunal of fact, judge or jury, to draw conclusions from the evidence presented. Allowing witnesses to express inferences risks prejudice, flawed reasoning, or misinterpretation due to limited understanding, which could be misleading.
- AG (Ruddy) v Kenny – seminal case – a long-standing rule of evidence is that, with limited exceptions, a witness may not give opinions on facts in issue but may only testify to facts personally observed. It is the role of the judge or jury to draw inferences, form opinions, and reach conclusions.
- R v Graat – in practice, the line between fact and opinion is often blurred. As Dickson J noted, the distinction between them is “tenuous and frequently false,” suggesting that while the theory is clear, applying it can be challenging.
3
Q
Expert opinion
A
- Expert evidence is admissible where the issue involves specialised knowledge beyond the experience of the tribunal of fact.
- As Kingsmill Moore J explained in AG (Ruddy) v Kenny, even if the tribunal had made the observations themselves, they might lack the expertise to identify key facts, assess them properly, or draw accurate inferences.
- Davie v Edinburgh Magistrates – the role of an expert is to provide the judge or jury with scientific criteria to help them independently evaluate the evidence and reach their own conclusions.
- McFadden v Murdock – expert evidence is admissible where particular skill and judgment are needed to explain results or trace causes.
- This typically includes fields like medicine, accountancy, actuarial science, and engineering.
- Expert opinion must remain within the expert’s specific field, and they are not permitted to comment on matters beyond it. While courts can appoint experts by statute in some cases, experts are generally selected and called by the parties as part of the adversarial process.
4
Q
Ultimate issue
A
- The ultimate issue rule traditionally barred witnesses from giving opinions on the key issues the court had to decide, to avoid encroaching on the role of the judge or jury. However, in practice, this rule was often ignored or sidestepped through careful phrasing. It is now largely seen as obsolete.
- McMullen v Farrell – Barron J. confirmed this shift, stating that there are cases where expert witnesses may indeed express opinions on the very questions the court must determine.
- Karen Millen Fashions Ltd v Dunnes Stores – O’Donnell J argued that experts should be allowed to state their conclusions, as long as the focus is on the reasons behind those conclusions. He emphasized that this approach makes sense in practical terms, as the court needs to understand both the reasoning and conclusions, rather than suppressing expert opinions altogether.
- Despite the decline of the ultimate issue rule, courts remain cautious about the uncritical acceptance of expert testimony on key issues. Judges retain the responsibility to make determinations, even when expert opinions are involved.
- F (Orse C) v. C. – Keane J. emphasized that while psychiatrists may assist in understanding mental illness, it is the court’s responsibility to decide whether a decree of nullity should be granted, not the psychiatrists, regardless of their expertise.
- In contrast to psychiatric evidence, which courts may approach with caution, expert testimony from more traditional fields like accountancy is often given greater deference.
- Murnaghan Bros v. O’Maoldomhnaigh – Murphy J. concluded that since the accountant’s testimony had not been challenged on the basis of its professional validity, there were no sufficient grounds to reject it.
5
Q
Weight of opinion
A
- The weight attached will depend on the circumstances; the tribunal is not obliged to accept the evidence. The factors which the court will take into account:
1. The qualification and expertise of the expert;
2. Extent of expert’s first hand knowledge;
3. Nature and extent of investigations carried out by the expert;
4. Level of recognition afforded by the courts to that area of expertise;
5. Whether views/methods are orthodox;
6. Extent to which facts on which opinion is based are proved in evidence. - People (AG) v Fennell – the court emphasized that the tribunal of fact is not required to prefer expert evidence over conflicting lay testimony – despite two expert psychiatrists testifying that the accused was insane, the jury chose to accept the lay evidence of witnesses which stated that the accused was acting normal, finding the accused sane and guilty.
- People (DPP) v Allen – the Court of Criminal Appeal highlighted the risk of the jury placing undue weight on expert DNA evidence, given its technical nature and ongoing development. The court cautioned that while the jury may rely on expert testimony, they should not assume the evidence is infallible.
- The trial judge is ought to direct the jury on how to properly evaluate such evidence to prevent overreliance.
- Cassidy v Wellman International Ltd – the SC held that when there is conflicting expert evidence, it is not the judge’s role to resolve the controversy. Keane CJ stated that the trial judge could not be criticized for preferring one expert’s evidence over another, provided the judge found the chosen expert’s testimony to be more consistent with the facts.
6
Q
Qualifications
A
- Galvin v Murray – Murray J – an expert is a person whose qualifications or expertise provide additional authority to their opinions or statements within their area of expertise. This serves as a threshold requirement for a witness to be regarded as an expert in court.
7
Q
Duties
A
- Emerald Meats Ltd v Minister for Agriculture – O’Donnell J emphasized that expert witnesses have an overriding duty to provide independent, unbiased, and objective evidence – experts should not simply accept their client’s instructions and must apply their critical faculties and expertise to the case. If experts fail to do this, their reports become no more than expensive calculations. The court expects experts, particularly in fields like accountancy, to offer realistic advice and to identify any exaggeration or unrealistic positions, which the court can then critically examine.
8
Q
the duties and responsibilities of expert witnesses
A
- The duties and responsibilities of expert witnesses, as outlined by Creswell J in National Justice Compania Naviera S.A v Prudential Assurance Co Ltd (The Ikarian Reefer) and reformulated by Toulmin J in Anglo Group Plc v Winther Brown & Co Ltd, include:
1. Experts must provide unbiased, independent assistance; they should not assume a role of an advocate.
2. They should only give evidence on technical matters within their expertise, not personal opinions or conclusions.
3. Experts must work with opposing experts to narrow issues and find common ground and define disagreements for a joint statement ordered by the court.
4. Expert evidence should be unbiased and unaffected by the litigation process.
5. Experts must disclose the facts or assumptions behind their opinion and not omit relevant information.
6. Experts should identify when an issue is outside their expertise.
7. If conclusions are based on incomplete facts, experts should explicitly state this.
8. Experts should be willing to revise their opinions if new information arises. - Although these principles have not yet been expressly approved in this jurisdiction, the Law Reform Commission has provisionally recommended the development of a formal guidance code for expert witnesses, based on the principles outlined.
9
Q
Criminal procedure
A
- Criminal Procedure Act 2010 requires the defence to notify the prosecution in advance of their intention to adduce expert evidence. Section 34 states:
1) An accused cannot call an expert witness or adduce expert evidence without court approval.
2) If the defence intends to call an expert witness or adduce expert evidence, notice must be given to the prosecution at least 10 days before the trial starts.
3) The notice must include:
a) the name and address of the expert witness,
b) any relevant report prepared by the expert, including any analysis or summary of findings.
5) The court will grant leave to adduce expert evidence if it meets the requirements of law and subsections (2) and (3) are complied with.
8) If leave is granted, the prosecution must have a reasonable opportunity to consider the expert’s report before the evidence is presented.
9) In this section—
o “expert evidence” means fact or opinion given by an expert, and
o “expert witness” means someone with relevant qualifications or experience.” - While these rules mark a significant shift from the previous regime, some flexibility exists.
- Subsection (4) allows the court to admit late expert evidence if the defence took all reasonable steps to obtain the report on time.
- Subsection (5)(b) and (c), leave must be granted where it wasn’t reasonably possible to give notice, or where unforeseen prosecution evidence arises and justice requires further examination.
- Markey v Minister for Justice – the applicant challenged the constitutionality of section 34 of the Criminal Procedure Act 2010, arguing that requiring advance notice and court leave to call expert witnesses breached the right to silence and Article 6 ECHR, and unfairly favoured the prosecution.
o The HC rejected the challenge, finding that s. 34 was a proportionate measure aimed at preventing trial by ambush and ensuring fairness – any interference with rights was limited, and trial judges would safeguard the accused’s constitutional protections.
10
Q
Civil procedure
A
- SI 254 and 255 of 2016 amend the Rules of the Superior Courts and introduce significant changes regarding expert evidence in civil proceedings before the High Court. The rules apply generally but some provisions are specific to actions in the Competition, Commercial, Chancery, and Non-Jury Lists.
- Order 20 Rule 11 requires a party intending to offer expert evidence at trial to state this in their pleadings, specifying the field of expertise and matters to be addressed. This does not apply to personal injuries actions.
- Order 39 Rule 58 restricts expert evidence to what is reasonably required to determine the case. Each party may offer evidence from only one expert per field per issue. The Court may allow additional experts if their evidence is “unavoidable in order to do justice between the parties”.
- Order 39 Rule 58(2) allows the Court to make various directions regarding expert evidence, including identifying the fields and experts allowed, setting timelines for report delivery or exchange, and ordering evidence to be given by a single joint expert.
- Order 39 Rules 59–61 apply only to the Commercial, Competition, Chancery, and Non-Jury Lists. Parties may submit written questions for clarification of another party’s expert report or a joint expert. The Court may exclude expert evidence or disallow expert fees for failure to answer. However, an expert is not obliged to answer questions that are disproportionate, unnecessary, or outside their expertise.
- Where experts hold contradicting opinions, the Judge may order them to meet privately, without the parties or their legal representatives, to discuss their evidence. They must then prepare a joint report outlining the agreed and disagreed evidence, which must be lodged with the Court and provided to the parties before trial.
- The Trial Judge may require the experts to be examined, cross-examined, or apply the “debate among experts” procedure. The experts will present the agreed evidence first, followed by the points of disagreement, after which they may debate. After the debate, the experts may be examined or cross-examined by counsel if directed by the Judge.
11
Q
Proof of foreign law
A
- Expert evidence is not admissible for domestic law but is required for foreign law.
- O’Callaghan v O’Sullivan – the Court held that foreign law must be proved as a fact through the testimony of competent experts with the necessary skill and knowledge. This is typically provided by someone qualified to practice or an academic from the relevant jurisdiction.
o The expert’s testimony, not the textbooks, is the evidence. A judge may refer to materials only if the evidence is unclear or if there is a conflict between experts, but should not conduct their own research into foreign law. - The court must decide for itself, using the material available, and choose between experts as it would for any scientific question. An issue of foreign law is treated as a matter of fact and does not have precedential value. If the same issue is raised in a future case, it must be proved again.
12
Q
Non-expert opinion
A
- Non-expert opinion evidence may be admissible in certain circumstances, divided into four categories:
1. Matters not capable of exact observation, where only an appreciation or extenuation is possible (e.g., estimating the speed of a car or the apparent age of a person).
2. Instances where primary facts and inferences are closely associated, making it difficult to separate them (e.g., observations about the condition of an object like “torn” or “old”).
3. Matters of ordinary experience, such as the sanity of a person.
4. A residual category where non-experts can express opinions on various everyday matters, as explained by Lavery J in AG (Ruddy) v Kenny, where ordinary people can offer useful opinions on incidents of daily life that are relevant but do not go to the main issues in the case.
13
Q
Statutory exceptions
A
- Certain statutory provisions allow admissibility of evidence regarding the belief and opinion of specified persons in particular contexts.
- Section 3(2) of the Offences against the State (Amendment) Act 1972 – permits evidence from a Garda Superintendent about a person’s membership in an unlawful organization under Section 21.
- The constitutionality of this provision was upheld in O’Leary v AG, where it was found not to infringe the presumption of innocence.
14
Q
proceeds of crime act 1996
A
- Proceeds of Crime Act 1996 allows for the seizure and disposal of crime proceeds. Under Section 8, a Chief Superintendent of An Garda Síochána can provide evidence in proceedings for an interim or interlocutory order to freeze assets, stating that:
1. The respondent possesses or controls specified property that constitutes proceeds of crime, or
2. The property was acquired with or in connection to proceeds of crime,
3. The property is valued at no less than €12,697.38, and
4. There are reasonable grounds for that belief.
5. This statement serves as evidence of the matter and property value. - Murphy v GM PB PC Ltd – held that Section 8 does not alter the onus of proof but makes the opinion of an authorized officer admissible if reasonable grounds exist. However, the court may refuse to act on such a statement depending on its basis.
15
Q
domestic violence act 1996
A
- Domestic Violence Act 1996 allows the applicant to present evidence that they have an equal or greater beneficial interest in a property than the respondent. This is relevant for barring orders regarding the place where the applicant resides, especially if the respondent has a legal or beneficial interest in the property. The evidence is not binding, and the judge is not required to act on it.
16
Q
- Competition (Amendment) Act 1996, Section 4
A
- Competition (Amendment) Act 1996, Section 4 permits the admissibility of opinions regarding economic principles and types of commercial agreements. However, the qualifications or experience requirements outlined in the section closely resemble common law standards, leading to the suggestion that this provision may be superfluous.
