The score is 3. The Optional Rethrow always includes a 1-throw penalty. Double jeopardy means you don't get two 1-throw penalties in situations like landing above 2m when that's in effect and you decide to take an Optional Rethrow rather than mark below the tree. Now it's only a 1-throw penalty.
Under the old Unplayable Lie rule, you could not call the Unplayable Lie until you had a lie to call unplayable. So, you first had to take the 2m penalty to bring the disc to the ground to create a lie. Then, take another penalty for Unplayable Lie if you didn't like your spot under the giant pine tree with low limbs. That double jeopardy penalty doesn't exist with Optional Rethrow because you can call it while the disc is still in the tree above 2m. You avoid the 2m penalty but still get the Optional Rethrow penalty instead. Hopefully this makes sense?
Rater of the tossed arc.