The list doesn't appear to be exhaustive. https://news.ycombinator.com/item?id=29066186
As far as I can tell that claim is purely based on speculation. It's possible that the death wasn't reported, or was somehow reported as "natural". However, it's impossible to know due to the lack of any basic information. (And I think improbable that Japan, of all places, would screw up the paperwork.)
Not to detract from the overall point — I think there are many reasons to dislike Kiwi Farms — but making dubious claims muddies the water.