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.

That’s what I’m saying too. Seinfeld’s comments were made in a more calm matter, but were way way way worse than Richards’.

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.

I don’t recall the lynching comments, only the several utterances of the n word, but I could be wrong. In either case it was vile and cannot be excused. What’s more telling to me is his behavior since; he was immediately apologetic and he has remained so for 20 years