I managed about ten minutes of that sermon, and at first I was pretty sure Chriswell was saying that being married to any unbeliever was evil, and the marriage should be ended. But later he does mention that he isn't talking about decent and upstanding non-Christians, but rather actively evil ones, with "filthy habits". I do wonder what specific behaviors he thinks qualifies.
I of course agree with him that there *are* behaviors that completely justify divorce. I suppose it's possible his message might do some good, if it leads some committed Christian man or woman to leave a badly abusive or just worthless spouse, despite their church's insistence that divorce is wicked.