I agree with most of what has been said here, but I think Salmo g. pointed out an important distinction regarding this case. The article states that the "town" where the store in question lies has a very small population. The "locals" probably couldn't even support a store on their own. Perhaps there was a "compelling" reason for the owners to set up shop directly across the reservation boundary....

I don't think this justifies a lawsuit, but it is a reason to sympathize with the Tribe somewhat, in my opinion.