I have no idea about the case at hand, but the thing that makes Fox unique among the major networks is exactly that: not only their history of twisting and even changing facts to support their viewpoint, but the whole idea of having a major "news" organization formally chartered to purvey only one side. It's entirely possible that CBS etc. have an editorial bias, and that it's reflected in their coverage. I'll grant that. But CBS wasn't founded expressly as the propaganda arm for a major party as Fox News was. To say so isn't naive, it's just an understanding of who created Fox News, when, and for what purpose.
The journalism world is chock full of minor and niche organizations that were founded as purely partisan outlets. Nobody reading Salon or Kos or watching MSNBC or RT should have any illusions about that. Arguably, the thing that makes Fox News unique is that it has been so successful. They do the same things that the minnows have always done, but they do them so well that they've gained such an enormous audience that they are mistaken to be an actual news site rather than a party house organ.
Nor is that unprecedented. In the early history of the Republic all newspapers were like that. This is just the first time a TV network was like that. And judging by copycats like MSNBC, it won't be the last.