What Really Happened?
He had apparently chased the dog and caught it close to a river, but the “feral beast” had bit him and in retaliation, he kicked it into the river. He had followed the trail to find the dog, but when he did, it was already surrounded by the police. He had been trying to call his partner when the dog saw him and barked. Afraid that the creature would come for revenge, he had fled.
He thought he had escaped until he saw the two officers following him. Fearing that he had been discovered, he had run.