As I understand it, it's not "point of use" but "point of delivery" that determines where taxes are owed.

My brother-in-law owns a furniture store in La Crosse, Wisconsin, which is just across the Mississippi River from La Crescent, Minnesota. One day someone called him on the phone and said, "I live in Minnesota. If I buy a bed from you, will you deliver it to me?" My brother-in-law answered, "Sure! I do it all the time." The caller replied, "OK, then, you owe Minnesota sales tax." The caller was a Minnesota tax auditor.

They audited the store's books, with my brother-in-law's full cooperation, and calculated what he owed them. The rule they applied was, if a customer picked up the furniture himself, it was a Wisconsin sale, but if the store delivered the furniture to Minnesota, it was a Minnesota sale. They charged him with the unpaid tax and interest, but no penalty, because they figured it was a good-faith mistake on his part. (It was.) Proof of good faith was the fact that he had collected and paid Wisconsin sales tax on all those sales. (I don't know if there is any difference in rates, but I doubt that he made any significant profit by paying to Wisconsin instead of Minnesota.)

Of course, that meant he had overpaid Wisconsin, and he should have been entitled to a refund from them, but he told me he wasn't going to bother applying for it. (This seems foolish to me, but it's his business.)

In the case of Indian tribes, treaties might be a factor. There might be a treaty or contract in which the tribe agreed to collect sales tax in exchange for some other privilege (or at least, someone is interpreting the treaty that way), even if the law wouldn't normally require them to collect sales tax.

I believe according to currrent federal law, states are enabled to make agreements with tribes.