I am not a fan of Randy White's spirituality, however I don't see where you get all of that out of what he is doing on this video.
I can't see that he thinks its funny, you can't see his face at that time. Nor do I see him making fun of the street preacher, is there more of the video?
__________________ For it is written, "As I live, says the Lord every knee shall bow to me, and every tongue shall give praise to God. (Romans 14:11- NASB)
Well, none of us were there. Who knows, but what the guy was saying something funny. Have you not ever been in those situations where people on the street are saying crazy things?