I know it is quibbling but QIN doesn't always get 50%. Treaty Indians get 50%. If there is no marine take by Tribes then they do get 50%. It's exactly like the NI shares on salmon and steelhead. Since NI don't take steelhead (we'll ignore the beach/Whidbey fisheries right now) each stream is shared 50:50. One for you, one for me.
In salmon, the NI side (especially) has already taken a big chunk in marine waters. Ultimately, this is why the in-river recs get cut off so often. Their (the NI) have taken the share ahead of them.
In Boldt, in Court, the sharing is Treaty/non-Treaty. If, somehow, the ocean troll by tribes harvested every last Quinault Chinook the QIN would have no allocation left under Boldt.
The above is what the Courts' have said. They also let the State and Tribes negotiate something different for whatever reasons they collectively have. Which is why transparency is critical.