I would emphasize that while any action that results in a Twist-Fail is definitely failed, the challenge that created it is rendered irrelevant, at least as far as this mission goes:

Eg:

Mice failed in a roll to find food to calm the nerves of a village? That might be a Twist involving conflict with surly mice. But after that conflict, the story doesn't go back to finding food for mice, the GM has to present a new challenge.