What is the test for overturning a finding of failure-of-proof?

"In the case where the trier of fact has expressly or implicitly concluded that the party with the burden of proof did not carry the burden and that party appeals, it is misleading to characterize the failure-of-proof issue as whether substantial evidence supports the judgment." (In re I.W. (2009) 180 Cal.App.4th 1517, 1528.) In this particular circumstance, the substantial evidence test focuses on "whether the appellant's evidence was (1) 'uncontradicted and unimpeached' and (2) 'of such a character and weight as to leave no room for a judicial determination that it was insufficient to support a finding.' " (Ibid., citing to Roesch v. De Mota (1944) 24 Cal.2d 563, 571.) The court reverses the lower court's decision, if and only if, the inquiry as noted above concludes that the "evidence compels a finding in favor of the appellant as a matter of law." (In re I.W., supra, at p. 1528, citing Roesch v. De Mota, supra, 24 Cal.2d at pp. 570-571.) Here, it does not.