Elsewhere in the interview Cuban said that Adam Silver had to get rid of Sterling and he understood why (sponsors, players, fans -- i.e. money). His point was one a broader one about what forms of racism and prejudice does society tolerate and what forms it doesn't. It is a form of racism/prejudice to cross the street when you see someone who makes you uncomfortable just on appearance. And that is an action that a lot more people do. Cuban is uncomfortable with the Sterling vote because he's honest with himself, and knows that his actions of crossing the street to avoid a black teenager he finds threatening is on the same continuum as Sterling's viewpoint. He doesn't necessarily think his reaction is the correct one -- in fact, he finds himself imperfect -- but it feels hypocritical to punish Sterling for his offense.
Is Cuban wrong? I guess that's up to interpretation. I don't think he's trying to make an argument in favor of Sterling. To me it seems like he's trying to move the conversation away from blaming Sterling towards people recognizing their own prejudices, of which he admits he is not immune. And people in this country have such a problem recognizing how their own, often intuitive, reactions towards race that there is value in having that discussion.