Impartiality and Independence in Expert Evidence

By Demi Swain

3 November 2022

Impartiality and Independence in Expert Evidence

A recent Federal Court decision serves as an important reminder to instructing solicitors on how best to brief experts, so as to ensure impartiality and independence of the expert’s evidence.

New Aim Pty Ltd v Leung [2022] FCA 722 concerned the alleged use of confidential information by former employees of New Aim Pty Ltd (New Aim).

At trial, New Aim relied on evidence obtained from an expert, Ms Fangyun (Lindy) Chen.¹ The extent of Ms Chen’s independence was called into question during cross examination.²

The Court ultimately rejected Ms Chen’s evidence in its entirety.³

Criticisms of how the expert was briefed

McElwaine J criticised the involvement of the instructing solicitors in briefing Ms Chen.

Critically:

1. Ms Chen produced her report within only 24 hours of receiving her letter of instruction from New Aim’s solicitors.⁴
2. The letter of instruction from New Aim’s solicitors was found to be misleading, as it implied that Ms Chen prospectively considered the issues. In fact, New Aim’s solicitors had already prepared a draft report prior to issuing the letter of instruction and therefore knew not only of what the answers to the issues would be, but also the form of the opinion.⁵
3. During cross examination, Ms Chen admitted to having conversations with, and sending drafts of her report, to the instructing solicitors for comment.⁶
4. Ms Chen also admitted that her report was a ‘collaboration’ between her and the instructing solicitors⁷ and that she could not confirm that ‘every word of every sentence was 100% written by her.’⁸

McElwaine J found the involvement of New Aim’s instructing solicitors went far beyond the scope of what was permissible.⁹ This conduct was “most concerning as it strikes at the very heart of the paramount and overriding duty that an independent expert has to assist the court impartially on matters relevant to the area of expertise of the witness”.¹⁰

The role of instructing solicitors in briefing experts

In briefing experts, the Court also considered, inter alia, the following factors instructing solicitors should take into account:

1. the guiding principle that “care should be taken to avoid any communication which may undermine, or appear to undermine, the independence of the expert”:¹¹
2. the consultation between instructing solicitors and experts must not “distort the substance of the witness’s opinion so that it loses its essential character as an independent report unaffected as to form or content by the exigencies of litigation”:¹² and
3. it is legitimate for instructing solicitors to “identify the real issues for the expert, to indicate when the report fails to direct itself to the real issues, to point out the obscurities and gaps in the reasoning, to indicate that the report fails to distinguish between the assumed facts and the opinion which is supposed to be based on them, and to indicate that the report does not explain how the opinion is substantially based on the expert’s specialised knowledge.”¹³

There are some circumstances in which an expert can agree words that have been put to them, without detracting from the independence and reliability of their expert report.¹⁴ However, such instances must be fully and frankly disclosed in any report.

New Aim’s instructing solicitors failed to disclose their methodology and the fact that a substantial portion of the expert’s final report had been prepared by them.¹⁵ Not only was this information withheld, but only ascertained during the course of cross-examination of Ms Chen. By not disclosing the methodology of preparing the expert’s report, the requirement of impartiality was substantially undermined¹⁶ and was held to be grossly unsatisfactory.¹⁷

Implications

This case is illustrative of the grave consequences of not appropriately briefing experts so as to maintain the independence and impartiality of their evidence.

Instructing solicitors should be cautious not to have inappropriate communications when retaining or instructing an independent expert, or be substantially involved in any drafting of the expert’s opinion.

As concluded by McElwaine J: “what occurred in this case should not be repeated”.¹⁸

A previous version of this article was published by The Law Society of Western Australia in the August 2022 edition of Brief which was authored by Demi Swain and Laura Cohn.

1. New Aim Pty Ltd v Leung [2022] FCA 722 (New Aim) at [28].
2. New Aim at [45]
3. New Aim at [77]
4. New Aim at [47]
5. New Aim at [74]
6. New Aim at [48]
7. New Aim at [60]
8. New Aim at [49]
9. New Aim at [45]
10. New Aim at [74]
11. New Aim at [65] citing Phosphate Co-operative Co of Aust Pty Ltd [1989] VR 665 at 683
12. New Aim at [68] citing Cross on Evidence (Electronic Version, LexisNexis, current to March 2022) at [29080]
13. Ibid
14. New Aim at [61] citing Harrington-Smith on Behalf of the Wongatha People v Western Australia (No 7) (2003) 3 FCR 424 at [18]-[19]
15. New Aim at [70]-[72]
16. Ibid
17. New Aim at [71]
18. New Aim at [76]

Disclaimer: The information published in this article is of a general nature and should not be construed as legal advice. Whilst we aim to provide timely, relevant and accurate information, the law may change and circumstances may differ. You should not therefore act in reliance on it without first obtaining specific legal advice.