“Here, the documents and communications at issue were shared by the AGO with the AGOs of other states in an effort to unify its strategy and conserve resources with regard to environmental litigation that the AGO has considered pursuing or predicted defending against. The very nature of disclosing these documents to the chief law enforcement officer in the respective state only bolsters that these documents were prepared in anticipation of litigation,” Associate Justice Nancy J. Waples wrote on behalf of the court.