I had a very heavily intoxicated indigenous individual tell me that once, lol.
I'm as cordial as anyone you'll ever meet but really don't take kindly to people crowding my personal space, and he did (probably unknowingly) so I told him in no mild terms to back up and he got offended. Either his wife or sister (?) came running over from her arts and crafts stand to pull him away and apologized. I guess he had just wanted to ask a question about my truck (an OBS Sierra with a mighty mouse V8).
But yeah, that's about it as far as negative interactions. There is a stretch of Arizona highway that runs through the western side of Navajo Nation and passing through it is unavoidable in order to reach God's Country if you're coming from PHX Metro but I'll usually willingly stop and buy some fry bread or something to help support these people, the poverty on the Rez is rife. My daughter copped like $150 worth of native crafted jewelry the last time we were up there this past Summer, FFS.