8 Opinion Evidence

8.1 General rule of inadmissibility

s 23: A statement of an opinion is not admissible in a proceeding, except as provided by s 24 or 25.

The reason for this is to objectify the subjective. This is to allow the jury to form their own opinions.

S 4 – Interpretation:

Opinion, in relation to a statement offered in evidence, means a statement of opinion that tends to prove or disprove a fact.

R v Munro – “it may in practice be difficult in some expert testimony to disentangle facts from inferences and opinions” but it must be done to “enable the jury better to evaluate competing theories.” FACTS: in this case a constable has created computer-generated diagrams that were presented as “fact when they were in most cases a reconstruction of what happened based on the constable’s opinion”. If they were to go to the jury then they should have been separated from the photos and the jury warned of their nature.

8.2 Rationale

Opinion may usurp the role of the fact finder, be based on inadmissible evidence and be highly unreliable.

Law Commission’s 1991 Preliminary Paper: “such evidence can be classified as unfairly prejudicial, misleading, confusing or time-wasting.”

APN NZ v Simunovich Fisheries – NZSC - “an opinion that a fact or circumstance is true or exists is not generally capable of establishing that the fact or circumstance is indeed true or does actually exist.”

Opinion allowed if directly relevant to a fact in issue:

R v Gooch – The fact in issue was whether D had come on to Mrs B. She said that he had “come onto” her making her feel “uncomfortable”. Defence submitted that this was opinion. Court held that it was not because the feelings of the witness were “part of the context” and therefore “a matter of fact, not opinion.” Mrs B’s feelings were found to be relevant, and of a probative value outweighing any illegitimate prejudice.

8.2 Exceptions

s 24 – GENERAL ADMISSIBILITY OF OPINIONS

A witness may state an opinion in evidence in a proceeding if that opinion is necessary to enable the witness to communicate, or the fact-finder to understand, what the witness saw, heard, or otherwise perceived.

Gives 2 criteria:

1. opinion must be based upon the personal experience of the witness;

2. expression of opinion is the only way it can be communicated.

Examples where it may be impossible to separate fact from opinion or explain the event differently:

“the car sped past me” – Speed

“an old man” – Age

“she was very upset – he was drunk” – emotional state

“the new car – it had been well used” – condition of things.

R v Bain – concerned the opinion of a constable as to whether david was ‘distressed’; held “the constable should describe his observations factually and, if the opinion is needed to communicate these, give that opinion only when the factual basis is clear.” E.g. “the constable could note the absence of particular signs of distress – crying, shaking, and the like.” Stating that he had “stopped shaking, that he was not tense, and that he was limp” are observations, not opinion.

Another witness said that David “seemed collected and relaxed”, court held it may be “unrealistic to expect any witness to have [a] level of detailed recall” and so this statement came under s 24.

It did not come under s 24 to state that David “seemed to be enjoying the hospitality of the [C] family as though he was there on a routine visit”. In such a case the witness must state what it is that david “did or said which caused him to think that”.

R v Warner – a witness after a rape said that the accused was “looking down in shame.” Held not to be opinion evidence as she was “conveying her observations of [D’s] demeanour when he was confronted following the incident.” Arguably the word “shame” is an inference that is going too far – I think.

S 25 – ADMISSIBILITY OF EXPERT OPINION EVIDENCE

(1) An opinion by an expert that is part of expert evidence offered in a proceeding is admissible if the fact-finder is likely to obtain substantial help from the opinion in understanding other evidence in the proceeding or in ascertaining any fact that is of consequence to the determination of the proceeding.

(2) An opinion by an expert is not inadmissible simply because it is about—

(a) an ultimate issue to be determined in a proceeding; or

(b) a matter of common knowledge. – subs 2 developed out of the CL.

(3) If an opinion by an expert is based on a fact that is outside the general body of knowledge that makes up the expertise of the expert, the opinion may be relied on by the fact-finder only if that fact is or will be proved or judicially noticed in the proceeding.

(4) If expert evidence about the sanity of a person is based in whole or in part on a statement that the person made to the expert about the person's state of mind, then—

(a) the statement of the person is admissible to establish the facts on which the expert's opinion is based; and

(b) neither the hearsay rule nor the previous consistent statements rule applies to evidence of the statement made by the person.

(5) Subsection (3) is subject to subsection (4).

Section 4 Interpretation

Expert means a person who has specialised...

Buy the full version of these notes or essay plans and more in our LAWS 307 Law of Evidence Notes.