It seems now that Harry's case against the Mail rests on slim foundations, and if he misled Doreen Lawrence into entering it then that's terrible. It definitely seems poorly-judged to have started it, either way.
On the other hand I feel quite sorry for him in one way : it looks increasingly like members of his circle must have been the ones leaking info in the 2000s. He fixates on hacking (which surely did happen but not in every case, and as far as we know, not provably in the DM's case) because he doesn't want to admit to himself that people he was friendly with & trusted back then may well have been the ones leaking- unethically but legally.
William didn't seem to have this as much, probably because he had more of a protective shell and a smaller, more vetted, circle. Harry seems for various reasons to have been more of an open book (and still is arguably) and this imo had attracted the wrong kind of people, often, dating back to the 2000s.