What is the test for the presumption of undue influence?

... The trial judge will commence his or her inquiry with the applicable presumption and will weigh all of the evidence in an attempt to ascertain, on a balance of probabilities, the transferor's actual intention. ... the presumption will only determine the result where there is insufficient evidence to rebut it on a balance of probabilities. Justice Goepel in Stone v. Campbell, 2008 BCSC 1518 at para. 44, 44 E.T.R. (3d) 146, applied the above instructions to the presumption of undue influence.