My understanding is that the wing breaks anyway in these tests. The important information is just how much abuse it takes before it breaks.
So long as it gets past n KN of force, or x degrees of flex then it's a pass, but the wing is tortured to breaking point so that they know where the breaking point is. After all, the test is to prove that the wing will permit the flight to land safely. Not to permit the next flight to depart on the same aircraft - that comes at a lower threshold.