(1) If the recipient, at the time of receipt, knows of the defect in the legal basis or if they learn of it later, then they are obliged to surrender the benefit from the moment of receipt or of obtaining knowledge of the defect as if the claim for surrender had been pending from this time on.
(2) If the recipient, in accepting the performance, violates a statutory prohibition or offends common decency, then they are under the same obligation from receipt of performance onwards.