He also wants the actual recording of the phone call in Arizona. He overlooks that his client is not a party to the case, but a witness, and not entitled to discovery or the phone call. He says it shouldn't have been disclosed to the defense because in his view it wasn't Brady (exculpatory.) He fails to mention it is Giglio (impeaching.)
Parsing his letter, and his repeated use of the words "purported" and "allegedly" when discussing the call from jail and the dialect spoken in it, here's where I think he's going. Law enforcement has leaked that the call was in the accuser's unique Fulani dialect, and they had to find a translator. The call was probably in Pulaar, which is a dialect of Fula spoken in Gambia. She spoke that as well, but perhaps not perfectly. If they used a translator who was only an expert in her dialect and not Pulaar (or vice-versa), the translator may have misinterpreted what she said in the call.
If the criminal charges are dropped against DSK, even if the DA's office doesn't file charges against her, ICE could take action to cancel or withdraw her green card charging fraud in her asylum application. She could be subject to removal (deportation.) If she's sent back to Guinea or a third country, she won't be here to pursue a civil suit for damages against DSK. That leaves her lawyers only with the libel suit against the Post. I don't think that's where they want to be.
What I really object to in his letter, aside from his stating as fact that DSK is guilty of a crime, are his repeated assertions that he's entitled to the fruits of the DA's investigation. As a witness, and not the defendant, she has no standing or right of criminal discovery. If she's charged with a crime and becomes a defendant, then she'll get them. Nor does he have a right to be told in advance of the press about the decision for an ADA not to participate in the case because she's married to an associate of DSK's lawyer. The New York Times reported all the details.
The accuser is a witness. She may be under criminal investigation. Only if DSK is convicted, does she achieve the status of crime victim. Even then, she's not entitled to all the things her lawyer is asking for and complaining about.