To be fair, calling Alan Greenspan an advocate, let alone a practitioner, of laissez-faire economics is kind of like calling the pope an atheist.

Since he was one of the contributors to Capitalism: The Unknown Ideal (1966, http://www.amazon.com/dp/0451147952), one of the more influential laissez-faire manifestos of the late 20th century, I think it's fair to say that he was an advocate of laissez-faire economics during at least a portion of his life.

Ok, but the blog post was clearly referring to Greenspan's actions/statements during his tenure as Chairman of the Federal Reserve by which time his credibility as an advocate of laissez-faire was out the window.