The reason for the Salish-Shidhe territory is because it surrounds Seattle on three sides. It's got an infamously porous border, and because it's a different country any of the powers-that-be in Seattle can't intrude on these operations. The Salish can definitely create problems for this bad guy, but they can't go after his Seattle holdings because they're also in a different country. By splitting his manufacturing and his distribution networks between two countries, he's made it hard for the authorities to cripple him all at once. And with the borders being so pathetic, it's not like the separation of governments will be a negative to his moving the product from one place to the other.
For the shadowrunners, the border might not be a big deal but it gives you as a GM the chance to really test them out with some law enforcement from another country, and to learn how to exploit these weaknesses that the bad guy is exploiting. And then, of course, you get to really lay it on thick with the comparisons between the runners and the bad guy, etc. It doesn't sound like your group really cares about the effects of their actions, but I get the impression that you want to make the players' actions mean something to them so you could try using that angle if you want.