Thanks for the correction, you're right. I'm going to leave the title of the submission for now though, to keep it consistent with the title of the actual blog post.
As with many corner cases of English grammar, I don't think there is such a decisive answer here that we can call him absolutely right or absolutely wrong, but FWIW his approach ('a' vs 'an' selected based upon the pronunciation of the acronym) is _much_ more common in my experience and is generally accepted.
