Final product when sp2 oxygen of acid is O18 in fischer esterification

[![enter image description here](https://i.stack.imgur.com/kn7iQ.jpg)](https://i.stack.imgur.com/kn7iQ.jpg)


In the question above, i was curious about option 3. If the carbonyl oxygen is O18, shouldn't half of the product we obtain contain O18 on the carbonyl since we have two possible leaving groups with equal probability of leaving?


