It took a long time, but I did watch this entire video.I hope you'll take the time to read this entire reply. The "angry black guy" as you call him said that black people have been fighting for years and they are prepared to fight once again and told the guy that white people will have a fight on their hands. That does not sound to me like threatening to beat white people up physically. Black people have always fought for their rights and recognition through demonstrations and getting racist laws changed and creating organizations like the NAACP. They have, for the most part, followed the non-violent approach of Dr. Martin Luther King. And sometimes, it seems, to no avail because the struggle still continues.
But, I found some interesting things about The National Policy Institute that the white guy was representing. In the book "The Myth of Race," by Robert Wald Sussman; The American Renaissance Foundation, an extremely right-wing organization was established by Jared Taylor, who serves as president of the New Century Foundation. Taylor has ties to a variety of domestic and international racists and extremists. He is on the editorial advisory board of Citizens Informer, the newspaper of the Council of Conservative Citizens, a virulently racist group whose website has referred to blacks as "a retrograde species of humanity" (Southern Poverty Law Center 1012). He has contributed to The Occidental Quarterly, a racist journal. He also has been a member of the board of directors of THE NATIONAL POLICY INSTITUTE, a self-styled racist think tank, and has received funding from this institute (Anti-Defamation League 2012).
So the black guy was in essence talking to someone who views him as a retrograde species of humanity, yet he remained surprisingly well controlled, up to date and well informed, in my view.