Engaging expert witnesses – practical advice

Expert evidence often plays a crucial role in building disputes, either in identifying defects, valuing works, or providing other technical information. Expert witnesses take on the role of an independent observer, with an overriding duty to assist the Court impartially on matters relevant to their expertise.[1] Typically, an expert will deliver their opinion in a report, in response to stated questions.[2]

The procedural rules governing expert evidence and expert reports are set out in:

  • Part 31 Division 2 to the Uniform Civil Procedure Rules 2005 (NSW) (UCPR);
  • the Expert Witness Code of Conduct, found in Schedule 7 to the UCPR; and
  • NSW Civil and Administrative Tribunal (NCAT) Procedural Direction 3.
    (collectively, the Codes)

The Codes create various procedural requirements for expert reports, for example, that the report contain an acknowledgement that the expert has read and agrees to be bound by the code of conduct.[3] For a detailed overview of these requirements, see our article here.

A common issue engaging experts

We have noticed a common scenario when parties obtain expert evidence:

A party engages an expert to inspect and provide a preliminary report. The report does not comply with the Codes. Later, litigation commences, and the expert either:

  • prepares a second more thorough report which complies with the Codes; or
  • puts on an affidavit acknowledging that their first report will be bound by the Codes.

No problem, the expert has fulfilled their obligations under the Codes… right?

Not necessarily. This approach may result in non-compliance with the Codes, which leads to two risks:

  1. the Court may hold that the expert report is inadmissible; or
  2. the Court may admit the report but give it little weight due to concerns regarding the expert’s credibility.

The Court may hold that the expert report is inadmissible

Courts have a broad discretion whether to admit into evidence expert reports which have been prepared in the scenario outlined above. In Welker & Ors v Rinehart & Anor (No 6),[4] the respondent sought to rely on expert reports which did not comply with the UCPR Code. The experts were not provided with a copy of the Code until after they had prepared their reports, meaning the reports did not contain an acknowledgement that the experts had read and agreed to be bound by the Code. The experts subsequently filed affidavits swearing they had since read the Code and agreed for their earlier report to be bound by it.

Rule 31.23(3) of the UCPR provides that an expert report which does not comply with the Code may not be admitted into evidence unless the Court orders otherwise. Ball J considered whether there was substantial compliance with the Code by examining the circumstances in which the report was prepared.[5] His Honour noted that the Court has a broad discretion whether to admit expert reports, but held that these particular reports were inadmissible because they:

  • did not give evidence justifying the assumptions underlying the expressed opinions;
  • lacked reasoning to support the conclusions in the report; and
  • contained generalised assertions which did not reflect the expert’s area of expertise.[6]

Although the Court retains a discretion when applying rule 31.23(3), this judgment demonstrates that non-compliant expert reports prepared in the above scenario may be deemed inadmissible.

The Court may give the expert report little weight 

Even if the Court admits an expert report prepared in the above scenario, there is a serious risk that the Court will give the report little evidentiary weight. In Smith v Ulan Coal Mines Ltd,[7] Campbell J exercised the discretion under rule 31.23(3) to admit an expert report filed by the plaintiff which did not strictly comply with the UCPR Code. His Honour made the following remarks in relation to rule 31.23(3):

“[…] Where it appears that the expert in preparing the report has been guided by impartiality, independence from the parties and a motivation to assist the Court rather than the party retaining him, there will have been substantial compliance with the Code. However mere retrospective inclusion of the required acknowledgment in an amended report will not satisfy the requirements of the sub-rule unless it can be shown that there has been substantial compliance in the sense I have already discussed.”[8] (emphasis added)

Although the report was technically admissible, it was given little weight at the final hearing. Hoeben CJ noted that in relation to the expert’s evidence that “there was a tendency to favour the plaintiff in some of the responses”.[9] The plaintiff’s claim failed, in part because his Honour was “not persuaded on balance that the plaintiff has given accurate evidence”.[10]

If parties prepare expert reports in the above scenario, they risk the Court drawing similar conclusions about the reliability of their expert evidence. If experts are not aware of their obligations under the Code at the time of preparing the report, including their overarching duty to the Court, this may raise doubts as to the expert’s credibility, and as a result, the persuasiveness of the expert report. These doubts may adversely impact the outcome of the proceedings, even if the reports are technically admissible.

Obligations in NCAT

Finally, parties should be aware that these same risks may exist in NCAT proceedings. Although NCAT is not usually bound by rules of evidence,[11] the Tribunal may direct that expert reports must comply with the NCAT Code.  In McGrath v The Owners – Strata Plan No 13631,[12] the Tribunal made this direction in respect of two expert reports, and the applicant failed to comply. As a result, the Tribunal refused to admit part of one report and the entirety of the other report into evidence.[13] The judgment was upheld on appeal.[14] This decision serves as a warning – the same risks set out above may apply to parties seeking to file expert evidence in NCAT proceedings.

Take home tips

When engaging expert witnesses, parties must be careful to comply with the Codes – this is true even when only a preliminary report is required.  In other words, parties must ensure when an expert is engaged that:

  • the expert is familiar with the Codes; and
  • the Codes are at the forefront of the expert’s mind when any preliminary inspections, condition reports or investigations are carried out.

This is to ensure that the credibility of the expert is not compromised in any subsequent litigation.

Bradbury Legal has extensive knowledge of the procedural rules governing expert evidence. We can assist in engaging expert witnesses in a manner which will best protect a party’s position at trial. For specialist and tailored advice, please contact a member of our team by phone on (02) 9030 7400 or by email at info@bradburylegal.com.au.

[1] UCPR Schedule 7 clause 2.

[2] UCPR r 31.21, 31.23(4).

[3] UCPR r 31.23(3); UCPR Schedule 7 clause 3(b); NCAT Procedural Direction 3 clause 19(a).

[4] [2012] NSWSC 160.

[5] Welker & Ors v Rinehart & Anor (No 6) [2012] NSWSC 160, [35].

[6] Welker & Ors v Rinehart & Anor (No 6) [2012] NSWSC 160, [40]–[44].

[7] [2019] NSWSC 1263.

[8] Smith v Ulan Coal Mines Ltd [2019] NSWSC 1263, [11].

[9] Smith v Ulan Coal Mines Ltd (No 2) [2020] NSWSC 416, [160].

[10] Smith v Ulan Coal Mines Ltd (No 2) [2020] NSWSC 416, [188].

[11] Civil and Administrative Tribunal Act 2013 (NSW) s 38(2).

[12] [2021] NSWCATAP 167.

[13] McGrath v The Owners – Strata Plan No 13631 [2021] NSWCATAP 167, [3].

[14] McGrath v The Owners – Strata Plan No 13631 [2021] NSWCATAP 167, [87].