I don't watch Maher that often so I can't comment, i never heard any of these alleged comments myself, but I don't know. KO is actually probably, to my knowledge the most sexist of left wing pundits. That I can think of, and of whom I have watched regularly.
I have personally written to him in the past, specifically when he staged sexist attacks against that beauty contestant who made those stupid remarks about gays. Liberal feminists definitely police their own - anyone who doubts this should look up the #mooreandme hashtag and check out Sady Doyle's campaign against both Michael Moore and KO for some outrageous rape comments they made. I participated in that as well - and both Moore and KO apologized.
Cons never police their own and then whine and cry about liberals not doing it. But liberals do! The problem with cons is they have zero clue of what is going on in liberal feminism and so they just project their own reactions onto "liberals". They assume. And of course make asses out of themselves! But what else is new!