Is your contention that paying for a service entitles you to zero bugs, ever?
the blog explains what issues they had and how they fixed them. this is good enough.
We're firmly in the realms of 'this thing is kind of smarter / faster at a task compared to me my employees, so I am contracting it to do that task'.
That doesn't mean 'if it fails, no payment'.
But I think it's too analogous to non-tech-products to hide behind a 'no refunds' policy. It's that good - there are consequences for it, I think.
It's a material difference in the product, not just "a bug."