Canada: The Broadening Disclosure Obligations For Expert Witnesses

Last Updated: April 23 2012

Article by Lana Finney and Sarah Robicheau *

Many environmental lawyers regularly work with environmental consultants who may ultimately act as expert witnesses. Many lawyers may also assume that nearly everything but the final report (such as preliminary drafts and information from counsel), will be protected by litigation privilege and/or solicitor and client privilege, even if one chooses to rely on the expert report and call the expert as a witness. For actions governed under the Rules of Civil Procedure,1 however, such information may not be so securely protected.

Rule 31.06(3) of the Rules of Civil Procedure provides a statutory exception to the general rule governing litigation privilege. It requires that unless (1) the materials were prepared in contemplation of litigation and for no other purpose, and (2) the party being examined undertakes not to call the expert as a witness, then a party is entitled on examination for discovery to "disclosure of the findings, opinions and conclusions of an expert engaged by or on behalf of the party being examined that are relevant to a matter in issue in the action and of the expert's name and address."

Consistent with a wider trend towards narrowing the protective scope of litigation privilege, the Court of Appeal has confirmed that the obligation under Rule 31.06(3) to disclose the "findings, opinions and conclusions" of an expert at the discovery stage in a proceeding will be construed extremely broadly.2

What can be Discovered?

The sentiment of the courts in interpreting and applying Rule 31.06(3) has been that the opposing party "ought to be able to explore with an expert whether he or she changed her views from draft to draft and, if so, why."3 In fact, in Browne (Litigation Guardian of) v Lavery, a 2001 decision of the Ontario Superior Court of Justice, the court mused in obiter that full and complete disclosure of an expert's file in the interests of justice might be appropriate.4

In Conceicao Farms Inc v Zeneca Corp, a 2006 decision of the Ontario Court of Appeal, the court made it clear that, while production obligations under Rule 31.06(3) do not extend quite that far, any information considered by the expert in reaching his or her final opinion is generally subject to disclosure under Rule 31.06(3).5 Furthermore, any preliminary findings, opinions or conclusions of the expert themselves must be disclosed, even if they ultimately differ from the final findings, opinions or conclusions provided in the expert report.6

Specifically, the following types of documents have been held to fall under the disclosure obligation of Rule 31.06(3):

  • factual information and data relied upon by the expert, such as texts or journals, calculations, engineering data, field notes, information obtained in interviews, raw data and records, to the extent that such information constitutes the "factual underpinnings in support of the opinions or conclusions" in the final report and that such information is not otherwise set out in the report;7
  • information communicated by counsel to the expert that is relied upon;8
  • preliminary drafts of the final expert report;9 and
  • any report of another author used and considered by the expert in the case at bar.10

Counsel should also be wary that describing consultations as "discussions only," "preliminary" or "informal" will not necessarily preclude the contents from disclosure.

What's Excluded?

Although factual information communicated by counsel and relied upon by the expert is likely subject to disclosure,11 the court has held that, in the absence of a specific reason for producing instruction letters from counsel to the expert, privilege over the document will prevail.12 The court has similarly found that "opinions or views [that] would not normally constitute 'findings' for the purposes of the rule" may be expunged from summaries or notes of discussions or interviews in which the expert engaged.13

Perhaps most importantly for those seeking to limit production of additional information, Kulyk v Cramp seems to indicate that if a final expert report clearly sets out the factual underpinnings in support of the final opinions or conclusions, no further production will be required.14 The exception to this principle is if there are internal ambiguities or contradictions in the report which require further information to explain.15

The 2010 Amendments to the Rules of Civil Procedure

The impact of the 2010 amendments to the Rules of Civil Procedure on expert disclosure obligations remains to be seen. It is possible that the limitless entitlement approach tentatively suggested in Browne and rejected in Conceicao may gain new legitimacy. In a recent Superior Court case dealing with whether surveillance evidence can be considered a document underpinning an expert's finding such that it might need to be produced, Master Short concluded:

I agree with [Justice Ferguson's] (then tentative) view [in Browne] and based on my analysis of the intent and purpose of the 2010 Rules amendments, it is my belief that his tentative view makes even more sense in 2011.16


The question of the scope of disclosure requirements under Rule 31.06(3) remains open for debate. It is generally prudent, however, to assume that draft reports, raw data and test scores, documents cited and relied upon (including other expert reports), information obtained through interviews, and similar "foundational" information may be exposed under Rule 31.06(3).

It is important to remember, however, that the goal of Rule 31.06(3) is to ensure appropriate disclosure of all facts relevant to an expert's opinion. It is not intended to serve as an alternative means of accessing documents. As such, opposing parties are entitled to the information, not the documents themselves.17 As a result, it is often acceptable to produce the type of information noted above in the form of a supplementary report, rather than provide the primary document containing the producible information.


* Lana Finney is a partner at Davis LLP and Sarah Robicheau is an associate at the same firm.

1 RRO 1990, Reg. 194 (made under the Courts of Justice Act, RSO 1990, c C.4).

2 Conceicao Farms Inc v Zeneca Corp (2006), 83 OR (3d) 792, 2006 CanLII 31976 (C.A.) [Conceicao].

3 Aviaco International Leasing Inc v Boeing Canada Inc, 2002 CarswellOnt 3266 (Sup. Ct.) at para 16.

4 Browne (Litigation Guardian of) v Lavery (2001), 58 OR (3d) 49 (Sup. Ct.) at paras 66-70.

5 Conceicao Farms Inc v Zeneca Corp (2006), 82 OR (3d) 229, 2006 CanLII 25345 (C.A.) at paras 37-43, overturned on other grounds in Conceicao, supra note 2, at para 16; see also para 14.

6 Cheaney v Peel Memorial Hospital (1990), 73 OR (2d) 794 (Sup. Ct.) at para 23.

7 Turner (Litigation Guardian of) v Dyck, 2002 CarswellOnt 4202, 2002 CanLII 5490 (Sup. Ct.) [Turner] at para 16; see also Allen v Oulahen (1992), 10 OR (3d) 613 (Ct. (Gen. Div.)) at paras 22, 26.

8 Ibid. (Turner) at para 16.

9 Aviaco International Leasing Inc v Boeing Canada Inc, 2002 CarswellOnt 3266, 2002 CanLII 21293 (Sup. Ct.) at paras 15-16; Conceicao, supra note 2, at paras 39-40.

10 Bazinet v Davies Harley Davidson, 2007 CarswellOnt 3979, 2007 CanLII 23158 (Sup. Ct.) at para 32.

11 Walker v Baskin Robbins, [2004] OJ No 1930 (Sup. Ct.) at para 7; see also Suchan v Casella (2006), 81 OR (3d) 615, 2006 CanLII 20844 (Sup. Ct.) at para 36.

12 Calvaruso v Nantais, [1992] OJ No 345 (Ct. (Gen. Div.)).

13 Arbesman v Meighen Demers, 2003 CarswellOnt 1798, 2003 CanLII 40972 (Sup. Ct.) at paras 10-11; see also Ontario (Attorney General) v Ballard Estate, [1996] OJ No 919 (Ct. (Gen. Div.)) and St. Elizabeth Home Society v Hamilton (City), 2004 CarswellOnt 367 (Sup. Ct.) at para 8.

14 Kulyk v Cramp, 2009 CarswellOnt 9572, 2009 CanLII 87112 (Sup. Ct.) at para 12; see also Kaptsis v Macias (1990), 74 OR (2d) 189 (H.C.) at para 10.

15 Ritorto v Ahmad (2006), 40 CPC (6th) 366 (Sup. Ct.) at paras 10-13.

16 Aherne v Chang, 2010 ONSC 2067, aff'd 2011 ONSC 3846, at para 75.

17 Ritorto v Ahmad (2006), 40 CPC (6th) 366 (Sup. Ct.) at paras 11-12; Conceicao, supra note 2. at paras 11-13.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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