This specific clause is about the Canada-Nova Scotia accord act. The Grand Banks is not concerned here, because it is part of the Canada-Newfoundland and Labrador accord area. The scenario under the Canada-Nova Scotia accord act will be more likely regarding the southern edge of the boundary with France, or near the United States coast.
If it's in international waters, there's no other appropriate authority. The clause of UNCLOS says it is the country where the continental shelf extends beyond 200 nautical miles that has authority. It's not a transboundary pool in that case.