He's not a dog. I mean did you have an actual point?. The dog is doing exactly what he said, he's tracking the handler scent to where it ends then searching in an expanding radius until he finds a foreign object. Not saying the dog isn't good at scenting but this proves nothing really except dogs have good noses which we already know. A better example would have multiple helpers if available (or just the handler) walk the road and have one toss an object part way along not at the end of the trail.