We have had this issue pop up twice in two weeks.
If a critical hit occurs, but the armor / toughness absorb the damage, what is the effect of the critical hit. For example, the Arbiter was hit in the body with an impact attack. Damage was 4 points (fully absorbed by armor and toughness), but the critical broke ribs and caused 5 levels of fatigue. Does the critical take effect? How does healing occur? It could be that this is handled in the rules and I have not found it.
Any help is appreciated.