R v CG, 2018 ONSC 6204 (Bell):

[14] There is a distinction to be drawn between the “foundational information” for the opinion —
which must be disclosed on the basis of an implied waiver of privilege over the facts underlying the
expert’s opinion that results from calling the expert as a witness — and draft reports (Moore, at para.
75).
[15] Litigation privilege yields where required to do so in order to meet the ends of justice: for
example, where the party seeking production of draft reports can show reasonable grounds to
suspect that counsel communicated with an expert witness in a manner likely to interfere with the
expert witness’ duties of independence and objectivity (Moore, at paras. 76-77). But, absent a
factual foundation to support a reasonable suspicion that counsel improperly influenced the expert —
and to be clear, no such allegation is made in this case — a party should not be allowed to demand
production of draft reports or notes of interactions between counsel and an expert witness (Moore,
at para. 78).
[16] Crown counsel has referred me to the decision in R. v. Friskie, [2001] 205 Sask. R. 208 (Prov.
Ct.). Although the issue in Friskie was the extent to which the Crown was entitled to disclosure of
materials provided to a defence expert, it is clear that what the Crown was seeking and what the
court ultimately ordered to be disclosed were materials that formed the foundation of the expert’s
report. Once an expert witness takes the stand, that witness can no longer be characterized as
offering private advice to a party; rather, they are offering an opinion for the assistance of the court
and the opposing party must be given access to the foundation of such opinions to test them
adequately (R. v. Stone, [1999] 2 S.C.R. 290, at para. 99, as cited in Friskie, at para. 19).
[17] The Crown has been provided with a copy of Dr. Pallandi’s notes. Unlike the “mini” reports at
issue in Friskie — which the court concluded at para. 28 were not draft reports but rather were
materials that related to the substance of the opinion evidence given — Dr. Pallandi’s draft report is
not material that formed the foundation of his report..
.
.
[20] Following the approach in Moore, I conclude that the litigation privilege which protects Dr.
Pallandi’s draft report was not automatically waived when Dr. Pallandi testified at the hearing.
While litigation privilege is not absolute, I find no basis upon which litigation privilege should yield
in this case.

[21] The defence is not required to disclose Dr. Pallandi’s draft report.