Credibility, demeanour, disclosure: deference and inconsequence: Cox v R [2023] UKPC 4

The deference of an appeal court to demeanour-based assessments of a witness’s credibility at trial is illustrated in Cox v R (Turks and Caicos Islands) [2023] UKPC 4, at [31], [34], [40].

There is always a kind of residual feeling that, even so, the credibility assessment may have been wrong. Deference avoids the need for appellate courts to deal with this. Plainly, the law has to be pragmatic about what risks are acceptable. Without challenging the correctness of the conclusion of this appeal, where circumstances supported the credibility assessment (see at [34(iv)], [46]-[47], [49]), we can still be left wondering about some general issues.

How reliable is an assessment of credibility based on demeanour? What does science tell us about this? Is an articulated warning about the need for caution in assessing credibility based on demeanour sufficient to counteract the risk of error, or might it be just a formulaic ritual?

Is it appropriate for an appellate court to defer to credibility assessments made at trial? Will technology, such as video recordings of trials, diminish the so-called advantage that the trial court has? Will the recently confirmed ability of appellate courts to reach what are really verdicts mean that appeals against conviction become replays of trials?

Should corroboration be required where the credibility of a witness is of central importance?

Another point brought to mind by this appeal is the inability of the courts to provide a remedy for unacceptable failure of timely disclosure if it does not affect the fairness of the trial (see [43]-[44]). Does unacceptable failure have no consequence? What does “unacceptable” mean?

Update: on 7 March 2023 the Chief Judge of the New Zealand High Court issued a practice note on disclosure in criminal cases (HCPN 2023/1). In the absence of an express power to punish for breach of the protocol, it may be assumed that relevant powers are costs orders under the Criminal Procedure Act 2011, s 364, and fines or imprisonment under the Contempt of Court Act  2019, s 16.

Hypothetical facts demonstrating the invalidity of laws: R v Hills, 2023 SCC 2

Courts in some legal systems can declare parliamentary legislation invalid. In at least some others courts may make a declaration that legislation is inconsistent (a DoI) with rights, but may take no further action against such legislation.

Deciding whether to declare legislation invalid can involve reasoning that has similarities to a debate held in the course of the production of a statute. Indeed, the reasoning process of the court may look - at least in part - very like the reasoning that a select committee may use in scrutinising a proposed enactment. This involves considering its implications by referring to hypotheticals.

In contrast, when a court is deciding whether to issue a DoI, it does not engage in a hypothetical exercise. It is the facts presented by the plaintiff, and accepted by the court, that form the ground for the DoI decision.

R  v Hills, 2023 SCC 2 illustrates engagement with hypotheticals where the validity of legislation had to be determined. The consideration of the application of the law to a reasonably realistic hypothetical led to a declaration that the impugned law was of no force and effect, and this declaration applied retrospectively.

However, where the most that the courts may do is issue a DoI, the approach (in New Zealand) is as illustrated in Attorney-General v Taylor [2017] NZCA 215, confirmed in Attorney-General v Taylor [2018] NZSC 104 and further illustrated in Make it 16 Inc v Attorney-General [2022] NZSC 134. When a DoI is issued there are procedural consequences for the legislature, provided for by ss 7A and 7B of the New Zealand Bill of Rights Act 1990. Those provisions were added to the Bill of Rights on 30 August 2022.

Although a DoI does not itself provide a remedy for the plaintiff in the instant case, the court may use interpretative techniques to reach a favourable result. For example, where the (since repealed) three strikes sentencing regime created an obvious injustice, the court was able to put the defendant within an exception to that regime: Fitzgerald v R [2021] NZSC 131 (noted here on 8 October 2021).

In Hills, the law was successfully challenged on the basis of how it would apply to others. The mandatory minimum sentence was found to be grossly disproportionate to the appropriate sentence for the same offence committed in a hypothetical set of facts in which the appellant’s hunting rifle was replaced with a paintball gun. The appropriate sentence was less than the mandatory minimum.

Unsuccessful challenges to the validity of legislation were made in the companion appeal, R v Hilbach, 2023 SCC 3. Here the offence was narrowly defined so there was little scope for hypotheticals that would call for sentences that would make the mandatory minimum sentence grossly disproportionate.