I enjoyed the article immensely. I have learned a few things differently, but the gist of the article is sound. In addition, the chief evangelist of the first century was a self proclamed Pharisee (Hebrews 3:5) and zealous for the Law.
As to the quote above, I have always believed it was because the Pharisees had such a high calling and had still failed. They were supposed to bring G-d near and had lead the people away from Him (Matthew 23:15). Jesus was much like the Pharisees of His day, and many modern Jewish scholars look at Jesus of the Gospels as a prime example of first century Pharisaic life. But He had given much to the Pharisees and had demanded much in return. They did not deliver.
Still, His desire was to save them, not to condemn them. His harsh words were to bring them to the light, not drive them into outer darkness. Witness His relationship with the Pharisee in John 3.