It was misleading for James to tell the Core Curriculum Committee that the chair of the Anthropology Department had endorsed his proposal. The chair of the Anthropology Department had told James that his proposal had her endorsement, but only if the draft proposal she saw included all the recommendations James would ultimately make to the Core Curriculum Committee.
The argument relies on the assumption that James thought that the chair of the Anthropology Department would have endorsed all of the recommendations that he proposed to the Core Curriculum Committee.