Can You Sign Away All Your Veteran Benefits?

I am trying to help a family friend, so I am not related to him. Her husband is elderly with significant health issues and needs care but they can't afford anything.  He retired honorably from full time military in the late 1960’s and then was in the reserves for over 20 years. He reached the rank of Lt. Colonel. I don't believe he was ever deployed to war but I'm not 100% sure. I asked his wife if he had any Veteran’s benefits and she told me no. According to his wife, he signed away all his pension and all military benefits for a payout  when he retired and they haven’t been in contact with the Army since. Is this something he could have done? Is there anything any he is entitled to still or any organization that could help him anyways? His wife doesn’t want to talk to anybody at the V.A because she believes it will be a waste of time. I don’t want to try and convince her to go if there truly is nothing available for him and he did sign away everything.