The in-game description for the Reek's basic says:
"Deal physical damage to target enemy and Expose them for 2 turns. This attack inflicts Trampled on all Light Side enemies."
This attack does NOT inflict Trampled on all Light Side enemies. It only inflicts Trampled on the target enemy.
I think the wording means to say "This attack also inflicts Trampled on Light Side enemies." This would indicate that it does not inflict Trampled on the target if the target is dark side, which it doesn't. This is the point that's trying to be conveyed, I think. But it says something completely