Instructors don't have the authority to override or make up PADI standards. If something is not specified in the standards, the instructor has no right to say it MUST be done this or that way. If he does he should definitely be reported to PADI. He might suggest you do it a way or another, plus factoring in the human ego factor of "i know better, you're getting punished for not listening to me" it might be in your best interest to just follow his advice, but he shouldn't be able to compel you to do it a way that is not specified in the standards.