There are a million ways to respond, but in order to engage the person in a dialogue I would plainly ask, “So… including people of color translates to lowering the bar? Tell me more about that.” I would ask questions around experiences to try and understand how the association come about, and then start asking questions as to objectivity — it this really true? Or something just assumed? Have you experienced the converse — hiring a diverse person when the bar wasn’t lowered? Maybe provide some examples. My goal would to be to show them that their statement doesn’t hold water and give them something to think of and be aware of in the future.