JOHN: I think you're safe.
[Because Cameron is a robot who doesn't have a soul.]
And Cameron phrased her claim in the present tense. I'm guessing the vast majority of today's Indians don't worry about losing their souls in photographs.
Still, this is the third time Terminator has mentioned Indians this season. (The first two references were to the Modoc War and Cabeza de Vaca.) As with Ugly Betty, it seems clear that someone on the writing staff favors Indians. No way do this many mentions happen by chance.
But wait, there's more
Later in the episode, Cameron inspects a dead cow and says there are no bullet wounds. A girl named Zoe responds, "What are you...Dr. Quinn, Medicine Woman?"
This isn't exactly a Native reference, but it's unusual. It would've made more sense to compare Cameron to Sherlock Holmes...Kojak...Hawaii Five-0...or Quincy, M.E. You know, someone who actually might apply detective skills to a dead body?
So it was a gratuitous Western reference, which shows the writers are thinking of cowboys and Indians. Which bolsters the point I made above.
For more on the subject, see TV Shows Featuring Indians.