able to shape these malleable principles so as to accommodate
the changing needs and mores of society, in order to achieve
 I see no other way to give meaning to the words of
McLachlin J. in Soulos, at para. 21: “This Court’s assertion that
a remedial constructive trust lies to prevent unjust enrichment
in cases such as Pettkus v. Becker should not be taken as
expunging from Canadian law the constructive trust in other circumstances where its availability has long been recognized.” See,
also, BNSF Railway Co. v. Teck Metals Ltd.,  B.C.J. No.
1714, 2016 BCCA 350, 89 B.C.L.R. (5th) 274, at paras. 45-55.
 I observe that McLachlin J. expected the tension
between the legal impulse and the equitable impulse to be reconciled and disciplined in specific instances by considering and
analogizing to past situations in which the courts have imposed
 As a roadmap to what follows, I begin with the first
route to a constructive trust: to remedy unjust enrichment. The
case was argued on this basis. (The second route, wrongful act or
wrongful gain, is not engaged.) But I am alive to the ambiguous
way the concept of “unjust enrichment” is sometimes used in the
authorities to describe, on the one hand, restitution for unjust
enrichment, that is, the idea of “giving back” what was taken,
and, on the other hand, disgorgement, that is, the idea of “giving
up” a gain that properly belongs to another. I would enlist both
the third route to a constructive trust — circumstances where
the availability of a trust has previously been recognized — and
the fourth route — where good conscience otherwise demands it
— to resolve the ambiguity.
 I now turn to the specific issues in this appeal.
G. Issue Two: Did the Application Judge Err in Finding the
Respondent had Made Out Her Claim in Unjust Enrichment?
 I begin by reviewing the elements of an unjust enrichment claim, and then turn to the appellant’s arguments that the
application judge erred in finding the respondent made out her
claim in unjust enrichment. Finally, I consider the jurisprudence
in the disappointed beneficiary cases, which are similar.
(1) The elements of unjust enrichment and the application
 For the court to find unjust enrichment, three elements
must be present, as the Supreme Court held in Pettkus: first, the
defendant’s enrichment; second, the plaintiff’s corresponding
deprivation; and third, the absence of any juristic reason for the