when crafting an item, if it is used in a retrieval task but you immediately use it for another recipe without closing the crafting table, it doesn't count towards the completion.
e.g. you have a quest that requires planks and one that requires sticks, if you use your log to craft planks and immediately craft sticks with the planks, the plank quest will not be completed.
alternatively, quests could be checked when the player inventory is modified for basically the same result.