It also helps to keep in mind the distinction between logical fallacies, used in a strict logical sense, and strength of argument. The case here is one of "what is the evidence to support a belief?", not "are the argument's predicates and conclusions logically valid in a strict sense?".

The original argument was that the article was "too quick to proclaim". The rejoinder was that this wasn't the article's conclusion, but that of an expert on the subject.

The discussion has been advanced, the initial claim invalidated, and additional relevant information provided.

To reject the conclusions of the article simply because of an appeal to authority, without also presenting a stronger claim that the authority is invalid, doesn't advance the argument.

To persist in that is tiresome.

A key question is whether or not the authority in question is credible. I've engaged in any number of discussions where showing credibility is at issue, and showing a particular source's good faith or record of admitting error (or not relitigating falsehoods) is crucial to qualifying or impeaching a witness. Again, you've not done this.

Paul Graham's "How to Disagree" is popular around here for various reasons. The derived graphic on hierarchy of disagreement is also strongly recommended.

http://www.paulgraham.com/disagree.html

https://commons.m.wikimedia.org/wiki/File:Graham%27s_Hierarc...

You might also want to catch up on your logical fallacies and how/when they're appropriate or not.

http://www.fallacyfiles.org/authorit.html http://www.skepdic.com/authorty.html http://rationalwiki.org/wiki/Argument_from_authority http://www.nizkor.org/features/fallacies/appeal-to-authority...

Note that key to these is the question of expertise.