Sorry to stir up the dust on this one again, but here's an extremely relevant quotation from the Rules (English) from WizKids Games:
For purposes of card text, a Creature who helps complete a Quest is not scoring! A Creature only “scores” when it is in your Ready Area at the start of your turn. When a Quest is completed, it is the Quest that scores, not the Creatures. [highlighting by me]
Of course, this is in addition to the Expert Rules and Questing section:
The Quarmageddon set introduced the Expert Rules that only permit a player to cull the actual dice that score and prohibit a player from receiving Glory unless he culls those dice. When using the Expert Rules with Questing, a player who completes a Quest can only cull the Creatures who successfully completed that Quest. Furthermore, a player cannot score Glory for a Quest unless he culls all the Creatures who completed that Quest. However, a player who does not wish to cull all of his Questing Creatures may still roll the Quest Die and receive its reward.