I think the implication is that the 'white' part is irrelevant to the sexual harassment she faced and just serves to muddy the waters. Would the treatment she experienced have been any more or less wrong had it been at the hands of non-white men? It's telling that the main harasser in her story, Ajit Nazre, is not white. And yet nowhere in her piece did she mention his ethnicity. It's not a huge leap to assume that the 'white' part of 'white men' is being added for effect and to try to curry sympathy for her cause by conflating two different forms of discrimination when she only experienced one. In fact one of her complaints was that Nazre, another person of Asian descent, was promoted over her. There's no evidence, nor has she ever made the accusation that she was the victim of racial discrimination.
Racism and sexism are two very different wrongs that are often found in the same situations. But they have very different origins, motivations, results and remedies. Therefore we should be careful when we talk about them not to conflate them when only one of them applies to a certain situation.
It is though, IMHO, wrong to call out Pao for blurring this line when so many of these diversity conversations also blur the lines. There are some fundamental differences between racism and sexism that necessitate taking different approaches to each problem and yet people seem so intent on grouping them together under a single 'diversity' label which is, to my mind, counterproductive.