psycholize
You had a pathfinding cell size of 30 whereas your sprites was 16x16 squares.
And it was possible that the hunter sprite reached its destination node as given by the pathfinder, but somehow was too far to collide with the hunted sprite.
A clear explanation of why that can happen with a cell size of 30 and a sprite size of 16 would probably require some drawings, and since I'm a bit lazy I'll ask you to trust me on that :D
All in all, it's probably better to have a cell size of 16 for sprite sizes of 16... (Though it might work with slightly bigger cell size but 30 was too much)