It looks to me like what they’re referring to is Michael Richards tirade being uncomparable to Jerry’s comments that were supporting the genocide. That’s how I read it, anyway.
But I mean he (Richards) was talking about lynching the guy at the Laugh Factory, so even as far as racism goes, that’s pretty fucking up there.
The clip I saw started with him saying “50 years ago you would be ‘strung up’” which yeah, 1950’s referring to a black man would be lynching.