Encourage the speaker to travel to Nigeria and countries around the Caspian Sea to gain better perspective on the purity of Oil Sands. Clarify and correct the terminology used, explaining that tar is a man-made product and that oil sands are mined.
You have obviously not done much travelling in your pathetic little life however to better educate yourself I suggest that you take a trip to Nigeria and to any of the countries surrounding the Caspian Sea. After that trip you will believe that Oil Sands product is as pure as the driven snow, in comparison. By the way tar is a man made product thus it is not mined - the name you are thinking of is oil sands.