Crying wolf?

There's a story from the life of St. Thomas Aquinas about how on a particular day the saint was minding his own business in his monastery when one of his brother monks cried out that a witch was flying by the window on a broomstick. St. Thomas hopped up and rushed to the window to see. The other monk laughed heartily at his successful prank. Pranks are usually a form of hostility and this particular monk seemed to resent St. Thomas's fame for his intellect and relished the chance to make him look foolish in front of the other brothers. St. Thomas responded that he thought it better to believe that a witch could fly past the window than that a monk could tell a deliberate lie.

The St. Thomas story came to my mind when I read that the nun who found Pope John Paul I's body now says that she lied about the details but had a really good excuse. If the nun was lying 40 years ago about who found the body, could she not lie now? If she believed that she had a good reason to lie then could she not believe that she has an even better reason to do so -- getting Pope John Paul I canonized--- today?  Should we not be as aghast as St. Thomas at the thought of a consecrated soul telling a deliberate lie?  Is a small, minor detail being cleared up or is the boy crying wolf...again?