No. Their concerns will have been 1) Is this book libelling someone identifiable who might have a case for their name/reputation being dragged into disrepute? and 2) Is this book claiming that a particular course of action miraculously cured a terminally ill man, in a way that might make other sufferers from the same condition think they too can be cured, and hence have a legal case for misleading medical information?
No to both. 'Cooper' is a fiction, and if SW showed the PRH legal team evidence of the final stages of the real courtcase, presumably it would have been possible to show them material that just showed they couldn't repay a loan -- there wouldn't be anything at that point to tie it to RW's theft from the Hemmingses, just an outstanding loan secured against their house.
And SW specifically has the consultant say he can't make a firm diagnosis:
‘I believe you have corticobasal degeneration, CBD. We can’t be absolutely certain about the diagnosis. There is no test, so we’ll only know at post-mortem.’
‘Post-mortem? When do you think that will be?’ Moth’s hands spread wide over his thighs, holding as much of himself as he could between his broad fingers.
‘Well, I would normally say six to eight years from onset. But yours seems to be very slow progressing as it’s already been six years since you first presented with a problem.’
So she's had the consultant say both that he can't firmly diagnose CBD and that whatever it is he has is very slow-progressing.
The next bit is all the narrator's subjective take on whatever the consultant has actually said:
The doctor looked at me as if I was a child; then he carried on trying to explain a rare degenerative brain disease that would take the beautiful man I’d loved since I was a teenager and destroy his body and then his mind as he fell into confusion and dementia, and end with him unable to swallow and probably choking to death on his own saliva. And there was nothing, absolutely nothing they could do about it. I could hardly breathe; the room was swimming. No, not Moth, don’t take him, you can’t take him, he’s everything, he’s all of it, all of me. No.
hence covered by the disclaimer about it being the author's 'personal experience':
Any medical information in this book is based on the author’s personal experience and should not be relied on as a substitute for professional advice. The author and publishers disclaim, as far as the law allows, any liability arising directly or indirectly from the use, or misuse, of any information contained in this book.