One would speculate that they were part of the same event; i.e., that the Black Sea flooded as a part of some larger phenomenon; your impact in the Shaat al Arab aera for example.
Yup, my mind has already 'darted' over to the Red Sea and the Persian Gulf because the Red Sea was land-locked and the Persian Gulf was completely dry during the last Ice Age. (They do mention flooding in the impact article too)