Does your pet dog always go with the one who is right in a argument?, sit on your lap and give the other half the daggers, I love my dog, he knows me so well.
Sorry, that is cute that your dog does that but it's not true. They can't understand what you are talking or arguing about. Dogs are usually just apprehensive or fearful when their people argue or even have loud discussions, so they will go where they feel safe or feel they need to protect someone
So you are assuming that the dog has a well enough grasp on the english language to understand what he is hearing and the cognitive ability to determine who is right in an argument? Seems rather far fetched to me.