I think no one here is trying to "blame" your son; just trying to warn you in regards to what your lawyer is telling you. I have an Aviation Lawyer friend. He has plenty of clients, almost all of them passengers.....I can't think of any pilots he has represented as of late. It is highly unlikely that the NTSB missed a broken "turbine wheel." I just hate to see someone swindled. P&W may settle just to "keep costs down" but without a change in the NTSB finding, what would that accomplish. I have seen drawn out court fights shatter those that file and fight them. Even when they "win," be it financial or factual, things are never the same.
Be careful is all folks are saying here, so sad your son's life was snuffed out at such an early age.
RadialGal