Removing an author name from Permalink

I created a plugin that would remove the author slug from the URL (permalink) ONLY for one specific author (“admin”). The goal of this plugin is that if John Smith writes a post, the URL would be http://www.example.com/johnsmith/post.html, but if admin writes a post, the permalink would be http://www.example.com/post.html.

This plugin worked perfectly until I just updated to 3.4. Now it doesn’t work. I can’t figure out which part of this code has changed in 3.4. Any help would be greatly appreciated!

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