This appears to be a case of a comedian who attempted to make a valid point - that racism is indeed a two-way street - but it badly backfired.
This kind of comedy is very hard to carry off easily. Chris Rock is not essentially a comparable situation - he parodies black culture and attitudes to an audience of mostly black people - and he does it very well. The vital point is that Chris Rock makes broad brush-stroke fun of racvial sterotyping - which is clearly not the case here.
Kramer was annoyed at someone behaving rudely and tried to incorporate his insult into his act as a 'Lenny Bruce' type observation - but he failed totally. The individual was insulted and took issue, and instead of difusing the sitation, Kramer added to it, and got invoved in an undignified exchange of insults, and was clearly unable to resuce the situation - or the audience - and was obliged to walk off.
To answer texol, this was racism - badly thought-out badly directed and badly received racism, and personal rudeness, which the individual attempted to cover as radical socal comentrary, and failed utterly.