She said that in the context of "There is nothing masculine/male about CS ..." and since gender was the subject of the dscussion you don't need a huge leap of faith to accept the comment as sexist.
As to the broom work, yes it's suitable t there, although not the subject of the post...
So why is it sexist to say "there is nothing masculine about CS"? If you say the opposite, surely it would be sexist, because it would imply that women are not made for CS. But saying "CS is not masculine" seems not sexist to me. Except that the whole question is rather uninteresting ("masculine" or not - who cares?).
As to the broom work, yes it's suitable t there, although not the subject of the post...