I notice a disturbing similarity between what Dumbledore did with the note he left with the invisibility cloak and the actions of H&C 1. Dumbledore increased Harry's trust in him by having his motives impugned by a note that he then discredited. Dumbledor arranged for Zabini to achieved the highest possible pinnacle of untrustworthiness and then H&C arranged for Zabini to impugn the motives of Dumbledore to Harry's mentor.