I believe they always die, just part of the linear story.  Would have been nice to save Carl.  Judge should have been exiled, then come back to the area later and she's a Zed.  

They missed a unique story opportunity there where survivors were talking about the judge not going hungry but they were.  "Civil Unrest at the Courthouse" Mission - Judge gets exiled, Carl takes over, you have the option to join at the courthouse later on with Carl saying, "I'm just a cop, these people need a leader," and possibly give a nod to Walking Dead where he talks about how his dad Rick would've handled this.