So far I’ve had this trigger from:
Wolves
Crocodile or giant crocodile or shaleback (green) or king shaleback
Werehyena ambusher or fall damage.
Addition while I was typing this: I havent noticed this before (havent tried it) but green shaleback can cause the “Unable to emote in current state” while you recoil from them swatting you I assume this applies to the stagger state from any damage. Could it be that the game considers you staggered for the sake of emotes when you aren’t currently staggered?