They did DNA on this tribe. Lots of the indians are traced to Asia. This tribe was traced to Polynesia!
The Polynesians were, indeed, phenomenal navigators (using wave refraction patterns from distant islands, etc.). The large canoes (especially if fitted with outriggers) would match the culture, too...
One wonders how such tropic-acclimated folk wound up in such a cold place, though. Probably not by choice; more likely the victims/passengers of large-scale ocean currents.
Of all the "paleo-dispersion" theories mentioned here, I might find this one most believable. Those Polynesians really "got around" -- even to remote, isolated islands that would be a navigation challenge, even with GPS!
The Tlingit, Haida, et al were raiders and slavers, trade was usually forced.