I was thinking more about John Patterson's criticism of the courtroom drama. In particular I was thinking about the third act problem that he identified in his article. He called it a crime against cinema and I do think he has a point. You might call it a cinematic crime to lessen the issue but here it is.
In a good movie, action drives the story. I don't mean action in terms of shooting guns or wrecking cars, I mean action in terms of the decisions that characters make. One active decision leads the character to the next beat of the story. For example, a character decides to 'leave home to save the princess'. He makes a decision that leads to more action on his part. It doesn't matter what he says in the dialogue, he is showing us his character by making decisions that lead to actions. The actions are where the story is told, especially in film. As a visual medium we watch our protagonist move from one decision to another, each one moving us closer to the resolution of the story.
The third act of the courtroom drama takes away the active decisions of the protagonist and the visual narrative stops. A courtroom drama ends up cutting from one lawyer to another to a reaction shot to a judges gavel to the agitated crowd and back again. The film story becomes a play. The thrust of the drama is now in legal arguments. There is no more action to be taken and we sit and contemplate and hope our hero wins.
What usually saves the third act is the new information that comes to light. A witness that we couldn't find, a legal precedent, or evidence that has been missed. The audience is still compelled to find out the truth. In a lot of ways they become a part of the jury even though they have been heavily biased by the writer who to root for.
So it's true that the third act of a legal thriller commits the cinematic crime of abandoning visual story telling. Yet, if you've done a good job of building a compelling story and more importantly, compelling characters, the audience will forgive and will be drawn into the climax of the picture.
As a post script, I couldn't help but think of another excellent courtroom drama - JFK.