What had happened was that a cultists had hit the paladin of the Raven Queen with a Baleful Polymorph, turning the paladin into a frog until the end of the cultist's next turn. The players at the table didn't know how long this would last, although one (not the player of the paladin) was pretty confident that it wouldn't be that long, because the game doesn't have save-or-die.
Anyway, the end of the cultist's next turn duly came around, and I told the player of the paladin that he turned back to his normal form. He then took his turn, and made some threat or admonition against the cultist. The cultist responded with something to the effect of "You can't beat me - I turned you into a frog, after all!" The paladin's player had his PC retort "Ah, but the Raven Queen turned me back."
There we have an example of a player taking narrative control on the back of an NPC's mechanic that the player knew nothing of until encountering it in the course of actual play. And at least for me, as a GM, that is the player of the paladin playing his role. And driving the story forward. On the back of a so-called "dissociated" mechanic.