Where there is a question as to the good faith of a transaction between parties, one of whom stands to the other in a position of active confidence, the burden of proving the good faith of the transaction is on the party who is in a position of active confidence. Illustrations. (a) The good faith of a sale by a client to an advocate is in question in a suit brought by the client. The burden of proving the good faith of the transaction is on the advocate. (b) The good faith of a sale by a son just come of age to a father is in question in a suit brought by the son. The burden of proving the good faith of the transaction is on the father.