That's called the necessary condition, the required, the necessary thing. The contrapositive would say, if the sauce isn't down to its last bits, he's not going to double dip his shrimp. But we were just given a counter example. When you're trying to contradict a conditional, it has nothing to do with negating or controposing. It just means provide one counter example. The form of a counter example is always something in which the trigger happens, but the outcome doesn't.