I'd like to invite Mr. Barton to defend his article here in this forum. This is the closest I can find to an email address for him at the Wallbuilders site "Contact Us" page:
Research Department 
The Research Department at WallBuilders receives hundreds of emails and letters, therefore it may be several months or more before a response is sent. We cannot guarantee that every inquiry will receive a reply. Our primary responsibility is to assist David Barton with multiple projects (such as articles, newsletters, and developing the resources provided through our catalog). We also respond to requests from Congressmen, Senators, judges, etc. (just to name a few). As with any organization, we have a finite set of resources with which to accomplish our mission. We would ask that you keep this in mind when you consider writing the research staff at WallBuilders. We also ask that you examine our website (especially the "Issues and Articles" section) before emailing a question to the Research Department. In an effort to continually improve the effectiveness of the WallBuilders site, we periodically post articles or make available resources that answer the most frequently asked questions we receive. info@wallbuilders.com
Can anyone else here provide better contact info? Mr. Barton doesn't seem to be too forthcoming with it on his web site.