What is the test for drawing an adverse inference in a family law case?

The case of Stetler v. Stetler is a 2013 Ontario Court of Appeal case. It was a family law case, and it was provided as an example of a case where an adverse inference was drawn regarding financial issues. Justice Lauwers wrote at paragraph 7: “I must draw an adverse inference from his failure to call his sister (the accountant) and his father who could have corroborated his evidence or given us the truth with respect to the amount of money that his father has paid him and whether or not he intends to collect on his mortgage debt.”