"I know, it's not your fault." This was true, Polyjuice copied a person down to the last cell in their body when brewed properly. There is a reason why it is supposed to be heavily monitored by the Ministry, but he was not too concerned about his higher ups questioning why he bought the materials for it often. In the event he ever got caught and a scandal broke out, the government was a lot more lenient with punishing their vital workers.