Matt thinks it's a compliment that Attean does not lead him back to the cabin because it's proof that he has earned Attean's respect.
We must remember that Attean primarily treasures the masculine skills of tracking, hunting, and fighting. So, when he stays at the bank instead of leading Matt back, Attean is indirectly saying that Matt is a competent tracker. That's a huge compliment.
Attean's increasing respect for Matt is also based on his gratefulness for the latter's efforts on behalf of his dog. Despite his injuries, Matt took it upon himself to brave the long journey to Attean's village. He also swam across the river.
When he arrived, Matt braved the forbidding welcome by Attean's grandmother to plead for help for Attean's dog. For his part, Attean understands his grandmother's hatred for white men. So, he is touched that Matt was willing to face such a welcome in order to save his dog.