I think he'd be much better off saying something like 'With hindsight perhaps I should have been more careful about what I chose to reveal but I was going through a tough time. I've been hurt about intrusions into my private life so I should have understood how parts of my book would impact negatively on others close to me.' Doubling down on the 'setting the record straight' nonsense is just tiresome at this stage.
But he genuinely thinks he did nothing wrong. He really is very dim and is utterly lacking in any sort of ability to reflect and be self-critical. Which is why he can't be a working royal again. Everyone will have to walk on eggshells around him, and who could be arsed with that?