I wonder if they were only scared of the aircraft, or would be just as hostile toward any visitors? If they would kill & eat anyone who walked up on them, it makes it seem like less of a big deal that their culture gets wiped out. As ethnocentric as it sounds, there is something to be said for civilization.
I bet there are church missionary groups planning a trip right now; they'll probably be the first outsiders to contact them. A lot of missionary types are convinced that the rapture can't occur until Christianity gets preached everywhere. My high school English teacher is one of them; she's now a preacher and has gone to remote areas of New Zealand, trying to hook up with the natives to preach the word. Thanks to them, there are random Christian churches in the middle of nowhere, New Zealand. Non-religious people will think this is all silly, maybe it is, but religion debate aside, it is at a minimum an excuse for cultures to rub off on each other, mostly us on them. The missionaries will bring candy bars, ipods, cell phones, Marlboros, bic lighters, toilet paper, and 101 other neat things they don't have. I have read about other tribes getting absorbed into mainstream in the rest of South America; one in particular just became welfare bums, because they could not see the point of money and capitalism, and working toward abstract financial goals. They had spent all of their waking hours securing food and shelter; when they wandered into society and the government, another concept they did not understand, gave them free food and shelter, all of their needs were met. They just sat around.