Supplementary Report of Own Expert

BCSC Rule 11-6(6) deals with the supplementary report of own expert. Are you familiar with this rule? If not, we will share a few details that you should be aware of. Let’s begin with the actual Rule 11-6(6) which states the following:

Supplementary report of own expert

(6) If, after an expert’s report is served under subrule (3) (a) or (4), the expert’s opinion changes in a material way and the party who served the report intends to tender that expert’s report at trial despite the change,

(a) the expert must, as soon as practicable, prepare a supplementary report and ensure that that supplementary report is provided to the party, and

(b) the party must promptly serve that supplementary report on every other party of record.

As it relates to serving of additional reports, it is always important to keep in mind the rules surrounding service of reports.  We refer to an article on this topic:

Timing Matters – Independent Medical Examinations.

It is always a good idea to review the following further principles as it relates to timely delivery of reports.  We refer to Tran v. Abbott, 2018 BCCA 365 (CanLII) in which a well known quote is highlighted as it pertains to the “modern philosophy”:

[17]        Rule 7‑6 is a rule of discovery. It is designed to balance the plaintiff’s advantage in obtaining expert opinions, by providing the defendant with access to the plaintiff for such prior to trial.


6         I take the position that this Rule is remedial and it is intended to give litigants the right to know each other’s case in advance. It is part of the modern philosophy that there should not be trials by ambush but that there should be full disclosure between the two parties in order (a) that the matter may be settled, without going to court, or (b) that, if it goes to court, there will be a trial with both sides being fully informed as to the other side’s case. 

These principles are reiterated in the case law:

“As this Court has made clear in a number of decisions, the rules with respect to the delivery and mandatory content of experts reports are intended to ensure that all expert reports are tendered in a timely way so that no party is ambushed or surprised at trial. Disputes over late-filed reports are to be avoided.”

Turning now to Rule 11-6(6), this specific rule is applicable in instances when a material change in the expert’s opinion occurs.  Once this has been identified, a supplemental report should be provided immediately if the initial report will be relied on, keeping in mind that the timing of the delivery of such a supplemental report will be reviewed by the opposing party and may be disputed if served late especially if prejudice may be caused to that party.  Also note in a published case, the Court stated the following:

Rule 11-6(6), in relation to a party’s own expert, is a provision designed to deal with circumstances where an expert’s opinion “changes in a material way”.

If the expert’s opinion changes in a “material” way, there are a few more tips that you should be aware of as noted in a 2022 decision of the BCSC:

[14]      The Rule contains an election. A party must decide whether it still seeks to rely on the expert report notwithstanding the material change. If it does, the party must promptly serve a supplementary report. In Perry at para. 10, Justice Savage said:

Rule 11-6(6) was not intended to allow experts to add either fresh opinions or bolster reasons upon reviewing for the first time or further reviewing material under the guise of there being a material change in their opinion. To provide otherwise would surely defeat the purpose of the notice provisions contained in Rules 11-6(3) and 11-6(4) and the requirement of R. 11-7(1).

(a)  be identified as a supplementary report,

(b)  be signed by the expert,

(c)   include the certification required under Rule 11-2(2), and

(d)  set out the change in the expert’s opinion and the reason for it.

Any supplemental report that is served under Rule 11-6(6) must therefore set out the material change in the opinion or the reason for it as noted in the 2022 decision, but should not be used as an attempt to:

  1. offer fresh opinions; or
  2. bolster reasons

upon reviewing for the first time or further reviewing material under the guise of there being a material change in their opinion.

These are matters for careful review if you are receiving or serving a supplemental report under this Rule.

The 2022 decision is an interesting one and does a great job in assisting with the interpretation of Rule 11-6(6).