The post is called How Confucius Proves Jesus and can be read here.
But first, let me point out that the title of the post is a little misleading. If you scroll down to the comments section, you'll see that it caused some people to misunderstand what Marshall was arguing. The argument is not that the existence of Confucius as a historical figure somehow proves that Jesus existed, too.
Rather, he's arguing that the Gospels are just as reliable as historical texts as the Analects. In fact, the gospels even have certain advantages over the Analects.
Despite this, virtually nobody debates whether Confucius existed, while the existence of Jesus as a historical figure is still hotly debated.
Therefore, we practice a double standard by refusing to accept the historicity of Jesus.
The only problem I would have with the argument is that there is more evidence to consider than just their respective writings. Confucius, for example, has had many descendants throughout history, unlike Christ.
But then, not every genealogical claim is true and verifiable.
It's an interesting question, and Marshall offers some interesting points.