New tricks
Oddly enough, it wasn’t the team who found the evidence, but Mr. Smith. According to him, it was clear why Kyle had led them to the tree: he missed his old partner! Smith had noticed other occasions when there was nothing to do that the dog seemed depressed. Their walks were the only thing that really got him going. It made him think of his work with John, something he clearly missed.
It appeared as though Kyle knew that John would come back if he discovered a new case. From the moment he saw John, his full attention was on him. Had he really set it all up just to see his old partner again? All arrows pointed to yes.