As I read it the appraisers are claiming confidentality. They're trying to city USPAP as a defense for violating a court order, setting USPAP against the law. If so, they can't do that. If they're arguing confidentiality on a contractual basis there will be legal precedents preventing that, too.
If I knock over a liquor store, I don't get to cite a contractual agreement with my accomplices as a defense against the court's inquiry into the matter.
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Now the critics might be right about the AG trying to shake down the appraisers for political purposes, but IRL the legal system does get used that way on a regular basis. Can't stop that from happening unless the lawyers can do so within the letter of the law.