Your thoughtful post history makes me hesitant to comment, but let me try. I spent the evening last night chatting to some divers who happen to know Don Shirley, Nuno Gomes and David Shaw personally. We discussed the event at length. Nuno Gomes who was the first person to touch down in Boesmansgat, refused several times to extract Deon's body. When he was ready for his world record dive he committed to taking a look for the body but attempted no recovery.
Please see
Articles
David Shaw decided to recover Deon's body, not because he was being coerced by Deon's family, but because he enjoyed the challenge and he wanted to return Deon's body to his parents as an act of kindness.
http://www.africandiver.com/articles/feature/shaw.pdf
I have no answer in regards to David's widow. Perhaps, and this is my own take on it, David had a responsibility to his wife himself and when he decided to dive, Deon Dreyer being at the bottom of Boesmansgat becomes incidental.
I don't know.
Maybe I should put a line in my will that prohibits my family from launching a life threatening recovery in the unfortunate instance that I might meet my end in some inhospitable place.