I’ve not reread TSP in light of Moth’s illness, but, if it had a legal read (and I would that assume it did — I don’t know if Michael Joseph specifically addressed this?), then I imagine the legal team will have been specifically careful to check that it wasn’t claiming to
(1) have discovered a miracle cure for a named terminal disease,
or to
(2) be advocating that sufferers from said disease should walk on hilly terrain for ten hours a day carrying a heavy load, for a couple of months at a time, to be cured.
Presumably the legal read was satisfied that YSP was just noting a marked (and temporary) in improvement in one man.
And in fairness, even if they were saying ‘Do this — it’s a miracle cure!’, if you have a horrible, debilitating condition that means you struggle to get out of bed or put on a backpack, and you fall easily, are you really going to drag yourself out walking up and down hills carrying a rucksack full of rocks, for weeks, to see if it helps you? And in the full knowledge thst in Moth’s case, it seems to last only as long as the exercise regime?
Admittedly, I haven’t read Landlines, where people say there’s a description of brain scans showing improvements.