I doubt the blog would be effective at swaying audiophools in any case. It is a religious belief... no amount of science will convince them.
However, free speech should not be silenced. The issue here is not whether the cable works or not. We all know the truth. The issue is can you report an event that you observed or quote a person that you interviewed on what happened.
The blog post would have conveyed the same message if it have simply stated that different conditions were being used for different cables (volume, track number but same music, etc.). Any reasonable person would have come up with the same conclusion... except audiophools who wouldn't care anyways as there is no way to scientifically convince them.
I'm not sure they have a legal case anyways. It is just not worth the fight. Knowing that the company tried to shut him up is a sign of what they are truly up to and enough bad press (again, falling on "deaf" ears, no pun intended.... as audiophools still will not be swayed the wiser).
Here is an article that sums it up, once again preaching to the choir:
http://www.skeptic.com/eskeptic/10-01-06/