The binding legal principles established are: (1) In an enrichment action based on condictio sine causa, the plaintiff must prove that money came into the hands of another without justifiable cause - not by gift, payment discharging a debt, promise, or other lawful ground; (2) Where an attorney receives funds into a trust account and distributes them in accordance with instructions from a person authorized by the client to give such instructions, there is lawful cause for the payments and no enrichment action lies; (3) For an enrichment claim to succeed, the plaintiff must prove both enrichment of the defendant and impoverishment of the plaintiff; (4) The quantum of enrichment is the lesser of the amount by which the recipient was enriched and the amount by which the claimant was impoverished; (5) Where payments reduce a credit loan account owed by the plaintiff to the defendant, the plaintiff's liability is reduced and there is no impoverishment; (6) In evaluating conflicting evidence based on recollections of events years earlier, courts must be cautious and rely on probabilities, considering factors such as the absence of contemporaneous documentation, consistency with proved facts, and whether the conduct of parties was consistent with their stated versions.