I don't know if it is relevant, but did Anthony specifically make payments to Palumbo for advising him? That is, did Palumbo bill Anthony for advising him on some basis (so much a month, or so much an hour), and was the advice written out? Does Palumbo use letterhead to correspond and invoice in which he represents himself to be an "expert?"
At some point, Palumbo might perhaps have some responsibility for practicing medicine without a license, if pharmaceuticals are involved in his written instructions.
If it's strictly friendly advice, then I don't see any basis for a liability claim.