I'll look for the book. It sounds like a good read.
Back in the 80's I was talking with a diver on Cozumel, who was telling a couple of us on the boat about losing those two, among many other interesting stories about some pretty extreme diving. It was only years later, when I picked up Shadow Divers, that I realized I had been chatting with a real dive legend, John Chatterton.
The death of the father and son team was a real tragedy, but they were doing some extremely high risk diving, and it doesn't take a lot for things to go south quickly.