I just realized the dog in the video you posted was not your dog. IMO, there is something off about that dog with him barking defensively at his handler on command. You can see when the handler pets him for the defensive bark, the dog looks unsure of his handler, suggesting to me, a temperament issue. If you don't have a fence, you can arrange to have someone come to your house at night while you are out with your dog on leash. Have the person hide before you take the dog out and know where he is hiding and have the person make some subtle noises of shake a bush. If your dog barks, praise with "good (whatever your command is going to be.) Then give the command again and have the person make some minor disturbance.