I think as a matter of law you're right. However as alluded to in my last post whether the jury will sufficiently understand this I'm not sure. They may well come in with a preconceived belief that this kind of scenario is exactly what manslaughter is for or should be for, and be unreceptive to being told it's not.
I've just thought, be prepared you all for this. It's coming if PR is found guilty of rape only. Hopefully Libby's family are.
In mitigation Mr Saxby steps up and tells the judge that it's not like this was a case of violent rape. As PR told the court earlier, Libby was all over him. He was conflicted. She was beautiful, naturally like any red bloodied male would he fancied her too, but he also thought of his wife and that he really shouldn't. But he did. He immediately wished he hadn't. Because of his wife. He had no reason to believe Libby was unable to consent. The jury have found as a matter of law otherwise but the fact remains Libby was more than happy at the time and was indeed only upset because he wouldn't stay for more. Not only is it a terrible misfortune for Libby and her family that Libby succumbed to a tragic accident, but PR has suffered terribly because if she hadn't died she wouldn't have dreamt of complaining she had been raped and he wouldn't have faced the terrible worry he's been put to through these proceedings. You just can't imagine as an innocent man how much worry he's had over potentially being convicted of her murder. It's ruined his life and he now needs medication for stress and depression. And anyway it's no different to like every night of the year young men and women meet at clubs and parties, usually worse for wear from drink, one thing leads to another and they end up in bed. Rarely is there any complaint afterwards. It's not that big a deal, it's modern life, just what young people do.
Thankfully the judge won't have been born yesterday and won't see it like that, but I bet he will have a go all the same.