Stop me if I'm wrong, but he was asking to be physically intimate with his wife, not for orgasms, not primal sex, not simple 'release'. And I really feel the need to stress that sex and maturbation are not the same thing. Granted they sometimes achieve the same results, but I think that's a stupid point to make.
Additionally, if he had started using porn, there's every chance that (sod's law) she'd be here making a post about how her husband watches porn and she feels like it's cheating and that he should be 'happy with what he gets' on her terms. A guy might say just as well that : well if she was a good wife and didn't want sex there's plenty of other things she could have done for him.... but there's no point going down that road. Again - this is a communication problem, not a sexual one.
Any way you look at this, it's neither of their faults for having the sex drive that they have, but they've been quite upfront with eachother that he needs it and is not getting it, and this has been a (contributing) factor to him moving out. He needed to be physically intimate. She wasn't providing it. Nobody was wrong, it just was what it was.
He wanted sex with his wife, and there was miscommunication between them as to why it wasn't happening. As I said before, it was bound to happen sooner or later.
I agree they should have gone to counselling, it could have helped them talk their problems out, but they decided that him moving out would be best.
So take it from that point.
A man who wants sex with his wife is basically told "no, go live somewhere else" - and regardless of what 'some men' might do - everyone has needs.
This was bound to happen at some point - a marriage without sex (or a hell of a lot of cuddles and petting to make up for it) is not a marriage. It's living with a lodger.
I really don't see why we should be beating on the guy here. Neither of them have done anything particularly wrong, and they were seperated. The only way I'd say she's right being so angry is if they specifically said this was a RACHEL break (friends hehe) i.e. no other people. If you don't have that discussion, again.... communication problem... not sexual
I really think you need to go into personal and couples therapy if you want to fix this. But I'll be blunt ... if you don't want to have sex with him, and you don't think this is going to change, you're just going to have the same issues for the rest of your lives, and you're better off making a fresh start now.
Good luck