No flips for you!
Appeal to authority exists when you say Person A is an authority on X, and they say Y, so Y is correct because A is an authority. This disregards whether Y is part of X, and the entire argument is that because A said it, it's right, based solely on his authority.I'm asserting that an appeal to authority is only as good as the character of the authority.
This doesn't apply if you provide the argument said by A, and rely on it's strength, or if Y is a technical issue and A is a legitimate authority on Y. In this case, you've ignored that the argument was presented while being credited and doesn't rely on the author being right solely based on their authority. And, you've also ignored that the author is actually a well-cited authority on this exact subject matter.
What you have done, though, is commit the genetic fallacy, which says that since Person A is horrible in way X, all things Person A says are also horrible.
I mean, if you're going to try to use an informal logical fallacy as a means of argument, do try not to commit a different one yourself in the process.
EDITL: and @PsyzhranV2 beat me to it. It's what I get for opening the reply window and then being called away and not checking before hitting submit.