I've just re-read that damning review of Robin's book, and yes, I think that's exactly what Robin is saying. It sounds on a par with this paragraph about the legal exemptions designed to exclude transwomen as rape counsellors.
The book notes :
"C]are should be taken to note the word “might”. For example, the situation may well depend on how well the trans person “passes”: if it is not possible to tell by looking at / listening to a trans woman that she is transgender then it is far less likely that the genuine occupational requirement would apply as compared with, say, a trans woman who does not pass as well and in a number of respects still looks male."
The reviewer 'The Legal Feminist' responds
The idea that “passing” is something that can or should ever be judged as a condition for employment is fraught with difficulty and embarrassment, both for anyone called upon to make such an invidious judgement, and for the trans person concerned. But even if that difficulty could be overcome, it doesn’t seem fanciful to think that the ability of a rape victim to detect when she is in the presence of a man may be heightened: her perception might not coincide with that of the manager. But more seriously than either of those objections, it should be self-evident that a rape victim who wishes to speak to a female counsellor should be granted that wish without question, and without any threat of subterfuge. It is difficult to imagine a more heartless message to convey to a rape victim than “The person you are sitting with, alone in a room, talking about your experience of rape, will either be a woman, or else a man who passes so well as female that you won’t be able to tell.”
According to Robin, there doesn't appear to be any situation, ever, where females can be without the presence of males.