Appeal to "actual" authority is still appeal to authority.
Consider an unproven theorem in the MetaMath database. Now consider an amateur mathematician, or perhaps a high school student finding and formalizing a proof. Irrespective of how (un)interesting the theorem is, Norman Megill and the users of MetaMath can verify (by pure reasoning) the theorem regardless of the authority status of the author of the proof.
Appeal to "actual authority" is just appeal to authority, which is a potential proxy for truth, and the phrase "appeal to authority" reminds us that sound reasoning and logic is superior to any reference to status or past achievements.
Consider an unproven theorem in the MetaMath database. Now consider an amateur mathematician, or perhaps a high school student finding and formalizing a proof. Irrespective of how (un)interesting the theorem is, Norman Megill and the users of MetaMath can verify (by pure reasoning) the theorem regardless of the authority status of the author of the proof.
Appeal to "actual authority" is just appeal to authority, which is a potential proxy for truth, and the phrase "appeal to authority" reminds us that sound reasoning and logic is superior to any reference to status or past achievements.