That tracker reading is liable to wobble quite a bit, not to mention anything she might sense the old-fashioned way. Like the tunnel shaking around her with a low rumble; like the suggestion of something vast around her, whining in pain.

Between him and his surface-self, after all, only one of them remembers what it was to feel obligated, and to loathe it. Unless she gives him a reason to come out, he won't.