They way I understand it----->if the retail ask Us, if we have a P-card, we are to say No. It is then up to the Retail to tell Us, about the Program. This all happens before the reveal. By this point, you also have your gas receipt and your in-store receipt. If you used "Your" P-card, then the retail will not have reason to explain or ask you about them.
Your problem will be, if you use your P-card without the Retail explanation it will be on your receipts. If you respond to the question on the survey, inaccurate, then your shop will be rejected.
If the Retail is doing their job, they will explain the P Program to you. And give you a P card after they have successfully explain the program. Even if you have one.
Keep in mind, the Client is one of the sponsors for the P-Program. Records can be checked. So if there is a plethora of points to be earned, earn them on the Right use and not on the wrong use.