It's illegal for the govt to pay for such advocacy. "no part of any appropriation contained in this Act shall be used for publicity or propaganda purposes not authorized by the Congress" and appropriated funds may not be used "in a general propaganda effort designed to aid a political party or candidates."
You're right, and I agree with you also that he should return the money. But on the question of principles, the PR firm didn't buy his opinion, he would have advocated for it anyways. btw I was just taking issue with the article.