“Egregious” failings in expert evidence: a shot across the bows from the Court of Appeal (Criminal Division)

The conjoined appeals in R v Byrne and ors. [2021] EWCA Crim 107 related to the safety of convictions arising from separate trials in which the Crown had instructed the same expert, Andrew Ager. Although the convictions were found to be safe, both Ager himself and the prosecution came in for stark criticism, particularly in light of previous high-profile failings in this area in R v Pabon [2018] EWCA Crim 420. The case provides the clearest reminder to all parties in criminal proceedings to ensure compliance with the requirements relating to expert evidence.

What are the practical implications of this case?

As well as providing a helpful reminder of the nature and scope of experts’ duties in criminal cases, and the importance of complying with them, three practical points of interest arise from the judgment.

  • First, the Court noted that the appellants’ position might have been different had they called a defence expert to challenge the substance of Ager’s evidence on key issues (as opposed to focussing on his conduct). Those instructed for the defence who suspect that a prosecution expert lacks the relevant expertise should therefore ensure any challenge sufficiently addresses issues with the content of his or her evidence.
  • Second, this appeal confirms the high, fact-sensitive bar for appealing against conviction in light of fresh evidence. While the Court expressed not inconsiderable disapproval of Ager’s conduct – and the conduct of the Crown – this did not affect the application of the test for an appeal against conviction. In other words, the Court of Appeal is unwilling to quash a conviction as an expression of disapproval even of “egregious” behaviour, where that behaviour does not ultimately impact the safety of the jury’s finding.
  • Third, the Court rejected the argument that Ager was not capable of giving expert evidence. In doing so, it adopted the “pragmatic” approach to determining expertise in criminal trials, as summarised in R v Pabon. This assessment will depend on the circumstances, and a lack of formal qualifications (as was the case for Ager) will not necessarily determine one way or the other whether a person is suitably expert in a particular area.

What was the background?

The Court of Appeal heard conjoined appeals against conviction brought by seven appellants, convicted across four different first instance trials, each of which took place between April 2016 and January 2019. All seven appellants were convicted of charges relating to improper investment activity in the carbon credit market. In each of these trials, the Crown instructed Ager to provide expert evidence on certain issues relevant to carbon credits, including on the critical issue of whether or not there existed a secondary market for carbon credits, and the extent to which this was widely known.

Following the conclusion of each of these four trials, Ager was instructed in a separate trial (Operation Balaban) which was not the subject of this appeal. In cross-examination during a voir dire, it was established (among other things) that Ager (i) had no training in his duties as an expert, (ii) had failed to comply with several obligations as an expert under the Criminal Procedure Rules, and (iii) had misled the expert jointly instructed for the defence, Dr Frunza, and attempted to dissuade him from giving evidence at trial.  Ager was abandoned as an expert for the Crown, and the jury were directed in no uncertain terms by the trial judge to ignore his evidence.

Following a public statement from the CPS that Ager would not be used as an expert witness in any further cases, each of the seven appellants in Byrne appealed against conviction on the basis that Ager’s evidence in their respective trials – and his failure to adhere to the principles and behaviours governing the conduct of expert witnesses – rendered their convictions unsafe.

What did the court decide?

Ultimately, the Court of Appeal found that none of the seven convictions were unsafe as a consequence of Ager’s evidence in those trials. This was a fact-specific conclusion applying the principles set by the Privy Council in Dial v Trinidad and Tobago [2005] UKPC 4; [2005] 1 WLR 1660, the ultimate question for the court being “whether, in the light of the fresh evidence, the convictions are unsafe” (at [32]). The court concluded they were not.

In reaching this conclusion, the Court noted that while the circumstances surrounding Ager’s evidence at these trials were clearly far from ideal, the substance of his evidence was essentially unchallenged by the defence, both at the original trials and on appeal. The Court also found that beyond Ager’s testimony, there was “abundant other evidence” that the carbon credit schemes in question were in fact improper, as Ager had broadly contended.

Notwithstanding its ultimate conclusion, the Court of Appeal did not miss the opportunity to point out that Ager’s “egregiousbehaviour” in Operation Balaban indicated a “clear preparedness” on his part to “disregard his basic duties as an expert“. It was not clear the extent to which this behaviour had been precisely replicated in the four trials at issue in Byrne. However, certain common themes were identified, including the fact that Ager:

  • Demonstrated “little or no understanding” of his duties as an expert;
  • Failed to sign the expert’s statement of understanding and declaration of truth;
  • Failed to conduct an independent review of the carbon credits market;
  • Failed to bring to the court’s attention material that might undermine his evidence; and
  • Misled and put inappropriate pressure on the expert instructed for the defence, Dr Frunza.

The Court’s criticism was not limited to Ager himself. The Crown’s failure in each of these cases to detect the underlying problems with Ager as a witness was a “notable error“, which the Crown needed to take “all necessary steps” to avoid in future.

Case details

  • Court: Court of Appeal (Criminal Division)
  • Judges: Fulford LJ, Holgate J, Sir Roderick Evans
  • Date of judgment: 3 February 2021

This article was first published on Lexis®PSL Corporate Crime and In-House Advisor on 9 February 2021.

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