The Alberta Court of King's Bench decision in Alberta Drywall & Stucco Supply (Calgary) Inc v Alberta Drywall & Stucco Supply Inc, 2023 ABKB 696 [Alberta Drywall] provides clarity on whether the production of an expert report before trial immediately waives privilege of all documents referred to by the expert in the preparation of that report.

In this decision released December 7, 2023, Justice G.S. Dunlop decided an application where the Defendant sought an order:

  1. Requiring the Plaintiff to provide the documents referred to and relied upon by the Plaintiff's expert in preparing a written report, which had not previously been disclosed in the documentary discovery process;
  2. Directing the Plaintiff's expert to attend Questioning on their report in advance of trial; and
  3. Directing the disclosure of documents received by the expert but not relied upon by the expert in forming the expert's opinion.

Background Facts

The Plaintiff retained an expert (the "Expert") who consulted several documents and engaged in discussions with the Plaintiff's principal ("Principal"), to ultimately produce a written report (the "Report"). The Report listed the information and documents relied upon by the Expert within the body of the Report under the heading "Procedures Performed and Documents Relied On".

The information relied on in preparation of the Report was as follows:

  • The filed pleadings;
  • Plaintiff Affidavit of Records sworn by the Principal;
  • Defendant Affidavit of Records and the continuing production of Defendant;
  • ADSSI-Calgary General Ledgers for the years ended January 31, 2013 and 2014;
  • Browne & Sons Plastering General Ledgers for the years ended January 31, 2013 and 2014;
  • Additional records requested from Defendant from ACE Point of Sale system; and
  • Discussions with Principal as well as additional documentary information provided by Principal, attached as an Appendix to the Report.1

In addition to that comprehensive summary, the Report included pinpoint references to documents in footnotes to the "Detailed Findings" section of the Report and in the twelve schedules which form part of the Report. With one exception, all the information relied upon by the Expert was disclosed to the Defendant – the exception being those discussions between the Expert and Principal.

The Defendant sought disclosure of all materials which the Expert consulted in the creation of the Report, whether or not those materials were in fact relied upon for the formation of the Report, as well as the discussions between the Expert and the Principal. The Plaintiff refused such disclosure on the grounds that the discussions with the Principal and other materials referenced by the Expert were protected by either litigation privilege or solicitor-client privilege.


Justice Dunlop categorized his decision into three heads, based on the three remedies sought by the Defendant.


There are two lines of authority in Alberta with respect to the privilege attached to expert reports. One line holds that privilege over an expert's report and the material the expert relied upon is not waived until the expert is called to testify at trial. The other line holds that privilege over such material is waived once the expert's report is served, since service of the report is a requirement before the expert is called at trial. This second line of authority presumes that the service of the expert report is ostensibly the equivalent of declaring that the expert will be called to testify during trial.

Justice Dunlop considered several cases to reconcile these competing lines of authority including R v Stone, [1999] 2 SCR 290 [Stone], where the Supreme Court of Canada considered whether an accused had waived privilege over an expert report provided by a psychiatrist, which the accused's counsel made explicit reference to in his opening statement to the jury.2

As explained by the Supreme Court in its decision, by disclosing portions of the report that favoured the accused, defence counsel could not then conceal the balance of the report as its contents might contradict or put into context what had been disclosed. The act of calling the expert to the stand certainly constituted the waiver of any privilege attached to the report. The Supreme Court noted that "once a witness takes the stand, he/she can no longer be characterized as offering private advice to a party. They are offering an opinion for the assistance of the court. As such, the opposing party must be given access to the foundation of such opinions to test them adequately."3 While Stone was a criminal case, Justice Dunlop affirmed that the same legal principles with respect to waiver of privilege apply in civil cases.4

In Ho v Connell, 2023 ABKB 133 [Ho], a decision released the same year as Alberta Drywall, Justice Feasby supported the position that the waiver of privilege with respect to foundational information used to prepare an expert's report occurs when the expert report is exchanged. Justice Feasby found that when a party delivers the expert report, this signals to the other side the crystalized intention to rely upon the expert's testimony at trial and, by extension, the foundational information underlying the expert's report.5

Justice Dunlop disagreed with the decision in Ho. He asserted that a party is free not to call an expert at trial despite having served that expert's report on the opposing party. Serving an expert's report just keeps the option open to call or not call that expert.6 As such, Justice Dunlop ruled that the Plaintiff did not waive privilege over the materials referred to by the Expert in serving the Report.


The Alberta Rules of Court provide for court-ordered Questioning of an expert only in exceptional circumstances.

Questioning experts before trial

5.37(1) The parties may agree, or in exceptional circumstances the Court may direct, that an expert be questioned by any party adverse in interest to the party proposing to call the expert witness at trial.7

The Defendant in Alberta Drywall submitted that it should be entitled to question the Expert as there were exceptional circumstances in this case; the matter was in case management, it was highly contentious, and the quantum of damages claimed was significant. Justice Dunlop concluded that none of those things was exceptional.8 As such, the request to question the Expert was denied.


The Defendant further submitted that it was not enough to know which documents and information the Expert relied upon; it also needed to know which documents and information were received but not relied upon.

In Lamont Health Care Centre v Delnor Construction Ltd, 2002 ABQB 1125 [Lamont], Justice Macklin ordered production of witness statements that the expert received. This order was made during the expert's cross-examination at trial, where the Court found that it was equally important for opposing counsel to be able to explore the factual information that the expert had but did not consider probative to the opinion formed. The Court explained that "to hold otherwise would be to allow single pieces of information or evidence to be cherry picked out of all of the information provided without the opposing side having the opportunity of determining from where it was picked and from what context it was picked."9

Although he agreed with the substance of the Lamont decision, Justice Dunlop concluded that at the pre-trial stage of the proceedings, such factual information remained privileged. If the Plaintiff exhibited conduct which demonstrated commitment to calling the Expert to testify at trial, such privilege may be found to have been waived.


Whether one is entitled to review all background documents informing the expert's opinion, the key consideration is how the conduct of the party serving the report is regarded objectively. If the party serving the expert report exhibits the intention of calling the expert to testify at trial, the materials consulted in the formation of the expert report may be producible. This is a context specific inquiry. Alberta Drywall indicates that this intention may be as express as providing a list of witnesses to be called at trial, or, the intention may be constructively found based on reference to the expert's report findings in an opening statement during trial.

With respect to the ability to question an expert in advance of trial, courts appear hesitant to accept that "exceptional circumstances" exist in typical commercial litigation disputes. Unless the expert's report would be of limited utility without Questioning, or, in cases where the credibility of the expert and the validity of their opinion is critical to the resolution of the issues, Courts appear unlikely to exercise their judicial discretion to direct Questioning of an expert in advance of trial.

In regard to production of materials provided to an expert, but not relied upon, Justice Dunlop's commentary provides important considerations for those seeking to pursue such production. The timeliness of an application to produce such information may significantly affect the likelihood of success, even if privilege has been waived. As a general principle, Courts are reluctant to facilitate the delay of trials by granting an adjournment to deal with additional production, especially when that production could have been sought in a pre-trial application. If the opportunity arises to obtain materials which could support the arguments at trial, litigants should act swiftly or risk compromising the success of gaining production.


1 Alberta Drywall & Stucco Supply (Calgary) v Alberta Drywall & Stucco Supply, 2023 ABKB 696 at para 8.

2 R v Stone, [1999] 2 SCR 290 at paras 97-99.

3 Ibid at para 99.

4 Supra note 1 at para 18.

5 Ho v Connell, 2023 ABKB 133 at para 26.

6 Supra note 1 at para 22.

7 Alberta Rules of Court, Alta Reg 124/2010, s 5.37(1).

8 Supra note 1 at para 32.

9 Lamont Health Care Centre v Delnor Construction Ltd, 2002 ABQB 1125 at para 12.

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.