What is the test for determining whether a person can be found guilty of fraud by reason of misusing money given to him as a gift?

In Goldsworthy v. Brickell and others, [1987] 1 All E.R. 853 (C.A. 1986), Lord Justice Nourse indicated (at p. 865) that the question to be answered is whether the gift was so large, or the transaction so improvident, "as not to be reasonably accounted for on the ground of friendship, relationship, charity or other ordinary motives on which ordinary men act."