If the salesperson does not believe you are the MS----->then you have done your job.
You have evaluated the Retail and objectively reported what you came across. Yes, the Client does tell his Retail that a MS is coming in. All the more for the Retail to be on its best behavior if they are otherwise not. The Manager of the retail depends on those bonuses too.
I like it when the Retail does not know I am the shopper. The Retail is loooking for a Shopper whom is this, that, and the other, and all they get is Me