I absolutely agree. I can't see anything wrong with my calculation above, which leads me to conclude the blog post or the article it is based on misunderstands

I absolutely agree. I can't see anything wrong with my calculation above, which leads me to conclude the blog post or the article it is based on misunderstands – or at the very least miscommunicates – the problem, if indeed there is one. The actual problem might be that standard statistical tests are difficult to use, but then isn't that why the theory had to be developed in the first place?