I agree with you that the author you are replying to has a weak opinion. However, that doesn't mean he hates women.
A careful look at what I wrote will reveal that my misogyny accusation was not directed at the author. Notice that the title of my post was "How does this get +5 insightful?" and then I speak of him and his post in the third person, while I make the misogyny accusation in the second person. In other words I was saying, "...don't let science get in the way of your [Slashdot moderators'] shit headed misogyny".
Calling him a misogynist because you don't like his opinion is a false argument ad hominem.
OK, so even if I had been calling the author a misogynist, it would only be ad hominem if I had used his misogyny as disproof of his premise. But my disproof of his premise was that it was contrary to scientific data. Even if I had gone on to claim he were a misogynist, which I didn't, it wouldn't have technically been ad hominem.
http://www.merriam-webster.com/dictionary/misogyny (a hatred of women)
OK, I think you are trying to say that a feeling of superiority to women is not the same as hatred. Yes, that's true, but that's not precisely the definition of misogyny I was picturing. See http://dictionary.reference.com/browse/misogyny (noun: hatred, dislike, or mistrust of women.). I think I would have been within my liberty to have accused of mistrust given the following from the author:
But if you need someone to get you to the moon--your best bet is still the guy
And yet, to be clear again, that's not what I was doing. I was noting that the quickness that this shot up to +5 (before anything else even had +3) was (yet more) evidence of the rampant misogyny in the ranks of the Slashdot moderation crowd. I'm happy to see that cooler heads eventually brought it all the way back down.