I think we ALL want to hear what FW has to say. But I think the fear of litigation is too strong. I also think it is more than that. JR has new wind in his sails now with this latest work of fiction, and he has been making public statements about suspecting a "family friend".
Obviously he can't actually NAME the "family friend" because he knows this person did not commit this crime. BUT his comments are meant as a veiled threat to this "family friend" (and I believe JR is referring to FW) to keep quiet about what they know because the accusation will follow if he says anything.
Now...there is absolutely NOTHING linking FW or his wife to that crime scene. Nothing. Not a hair, fiber or print. Unlike the parents, whose fibers and a hair from Patsy's forearm were found either on the body, or on articles at the crime scene.
I believe this threat of renewed accusation is enough to keep FW silent. His life was ruined once. 15 years have gone by. He would not want to have it happen again. Even if FW were to counter-sue, and even though there is no evidence with which LE could ever indict or arrest him, there would be renewed speculation and suspicion and I think he needs to keep himself as far away from that as he can. He has to consider himself and his own family first. While he may wish there would be justice for JB, he also knows Boulder will never prosecute ANY R for this crime. It just isn't worth it, and I don't blame him. If he was dealing with a DA that actually intended to prosecute no matter WHO the killer was, maybe he'd reconsider. But I don't think he will.