I think "selling consultant" is just a euphemism for real estate agent or broker. I looked up real estate selling consultants in NC and came up with dozens in one city, all of whom were licensed real estate agents and/or brokers.
I agree that NCDude may be using "selling consultant" in a way different than states define the term. NCDude might be referring to his real estate agent/broker as a selling consultant.
States generally require that both real estate agents and selling consultants hold a state real estate license, but the jobs of the agent/broker and the consultant are generally quite different. The first helps a buyer/seller purchase or sell a property and the second helps someone (generally an investor) make a decision on the purchase or sale of property based on market trends (and other factors) in the area.
A purchaser/investor looking to buy property for a grocery store might hire a consultant to research the needs of a particular area. The information gathered can (and usually will) include census data. If the proposed grocery store is geared toward a specific ethnic population, for example, the investor may be looking to purchase property where there is an existing demonstrated market for the foods or the investor may be looking to purchase property where there is a demand but no other grocery stores of its type existing. The racial or ethnic makeup of an area can be an important determiner in what property to buy.
A real estate agent or broker is hired (generally on a commission basis) to show or sell property based on a purchasers wants or needs. An agent/broker can run afoul of the law if only certain properties are shown based on a buyer/seller's race or ethnicity (or gender, etc).
The answer to NCDude's question can depend on what exactly his purpose is/was in hiring the "consultant" and why the consultant disclosed what he did.