Well, it does say they "won't act on reverse-racism or reverse-sexism", so, depending on how you interpret that I can see what he's trying to say at least. "Endorses" is strong, but "ignores" would be correct. And one could imply something about the authors of this CoC from that.
If you take action to ban all things in some group A, and then make an explicit exception to not ban some subgroup B, it seems pretty close to endorsing subgroup B. If they had not called the exception, but instead just ignored reports about it, that would seem more like ignoring.
For a comparison, say you have a party at your house that gets out of hand. Too many strangers show up. So you explicitly state that all guests are required to leave. There is a difference between telling some people they can stay (or saying I won't call the cops if you stay, but I'll call the cops on anyone else who stays) and just ignoring the few people who don't leave.
That is generally what reverse racism and reverse sexism is understood to mean. People on either side of the argument, when asked to define those two terms, would give similar definitions.
If anything betrays their political bent, it is that they view this as a negative thing. But the same could be said of those who do not view this as a negative thing.
Honestly I assumed it because his comments just read like a bitter MRA. But if you want, you can click his profile and confirm it for yourself like I did.
"Why do you assume a member who spouts KKK rhetoric is a white person?!?" -okasaki