In case anyone finds this a useful recap, I think it's fair to say the main issue is that readers and fans of The Salt Path and RW are incredibly upset from being duped by the "true" story of the Salt Path.
That story hinges on the Winn's becoming homeless (bad luck and a bad investment), near penniless (loss of income of holiday rental & court costs) and facing the awful terror of a tentative terminal diagnosis (clinical, professional judgement) from a long term health issue. All of this drives the Winns to walk the path and undertake a journey of redemption, coming out the other side "reborn" as per traditional "heroes journey" narratives.
What has come to light is that what happened in reality, even with RW's rebuttal and letters, could never fit this emotionally appealing story arc. Thus readers are rightfully upset who invested emotionally and empathetically to the Winns plight.
The story arc now fails as a true story because the Winn's homelessness was in fact the ultimate result of, at best "accounting mistakes", at worse, embezzlement, as well as somehow allowing the home you love to be collateral for a huge loan required to fix those "accounting mistakes." This isn't bad luck. Their actions and choices caused their situation - it was in, not out of, their hands. Our emotions do not sympathise heavily in this scenario compared with the book.
Meanwhile, the tentative terminal diagnosis comes in 2015, two years after the walk. The very essence of The Salt Path narrative is driven by RW's desperation of losing Moth to this illness. But in reality, they walked it with simply not knowing what he had. No doubt his struggles were and are real, but the picture painted by the book is that he is dying, or perceived to be dying in the eyes of RW. This is where readers have been emotionally duped, and where the narrative seriously departs from the true chain of events.
What we instead have is a couple who lost their family home due to their own bad, allegedly criminal, choices. A husband who has some long term unknown and intermittent problem with his movement. And finally, their walk of the SWCP for a couple of months while they work out what to do. Herein lies the deceipt to the reader.
[Note: the tentative terminal diagnosis comes in 2015 which must have been awful for them. Around the same time RW starts to write the book. It's inexcusable, but I can perhaps start to understand how this terminal diagnosis crept into the Salt Path narrative when she was writing and looking for a hook to hang the story on. If only she'd been upfront.]