We don't know how the brief fit into the context of the case. It is pointless to speculate.
I guess the two things I would say is...
First when I hear the media submits a brief, I think hmm why does the media even have an interest in this case? so to me it seems like the context should be somewhat relevant.
But in terms of media bias? Well there are many possible explanation for the disconnect that have nothing to do with media bias.
The focus of the media attention has not been claiming there is public proof of a crime..rathar just proof the white house lied to the public about the facts of the case. Thats really all the media has said. I personally think it will come out that Fitzgerald has proof of a crime, but the media certainly hasnt claimed to have proof a crime. So far the media has just proof that the White House has lied about the
facts. (which of course suggests they know they did something wrong)(maybe not illegal but certainly immoral).