In 2010 my son signed a 100,000 dollar settlement being diagnose with PTSD I don't think he was not mentally well to sign such a settlement without a lawyer. And I think the contract company lawyers walked him though settling for this. He still is...
First, I am not clear what you mean by "contract company lawyer."
If he was mentally incompetent at the time he executed the release and if that can be proven that he was It is possible attack the release. That will be difficult. Further, since the release is a contract, in order to rescind or undo the contract you must also tender the proceeds. In this case that would be the 100k. If your son was represented by counsel and the settlement was improperly conducted then you may have a cause of action against the lawyers who represented him.