I didn't know what Simpson's Paradox was, but I didn't find it surprising at all. After all, the numbers showed that these were two different experiments with two different distributions of large and small kidney stones.
Stopped reading the article afterwards, because if it already overhypes greatly at this early point in the article, what am I to expect at later points?
Most people (smart people included) find Simpson's paradox very surprising when they first hear of it, so it's possible you missed something. It might be worth taking another look.
Stopped reading the article afterwards, because if it already overhypes greatly at this early point in the article, what am I to expect at later points?