It would seem that since Legends of Kalidasia: Heroes of the Heragul was released, there was an incorrectly stated rule in the main rulebook. On Page 19,
Near the bottom of the first column, the following line reads: “For each die rolled which is greater than the target’s critical value, a critical hit is generated.” This is incorrect as seen in most of my how to play videos. Any die which is greater than or equal to the target’s critical value will generate a critical hit.
This has been updated in the January 2019 Heroes of the Heragul FAQ.