A dog was tangled up in a wire fence until an officer cuts it free. It's hard to tell exactly how the dog was stuck, but by the sounds the poor pup makes while the officer cuts through the wiring, he was there for too long. The dog wags its tail when the officer comes near to help him; I'd be excited too if I was stuck on a fence and someone with thumbs showed up.
Once the dog is free, he starts limping away, and the officer then gets distracted by an old woman who probably called him in the first place once she saw the dog stuck on the fence. But he doesn't have time to chit chat with the sweet old lady because the dog is now on the run. On the limp.
The officers thinks he lost the now freed dog and then, to his surprise, he finds the dog sitting somewhere unusual. Maybe it was the dog's way of letting the officer know that the man who frees him is the man who owns him. At least until the dog saves the officer's life once and thus returns the favor.