I disagree to some extent. Fear of death changes the scope of everything. Because of this fear, there will be techniques that are used in the ring, that won't seem so useful anymore, because of the risk of death. This has the same effect on the other side as well, but the person who consistently trains in a manner that is not confined by rules, I believe will have the advantage. Additionally, the purpose for the training makes a large impact on the outcome. If one is training for the sole purpose of winning in the ring and scoring points, they are not training with the idea that they are fighting for their life or the lives of their loved ones. In fact, the reality of death is far from their minds as they train. This too, impacts what they do on the street when their lives are on the line.
Sure on the street there will be elements that are familiar to them, but I believe they will find real self defense or fighting for their life rather unfamiliar.
When I talk about on the street self defense, I am not talking about someone's ego getting bruised in the club so he starts swinging, or someone grabbed his girlfriend's ***. I am talking a legitimate surprise life and death situation.
Well, who does train with a genuine fear of death? In order not to have the fear disappear from training, there would presumably have to be a pretty near percieved threat of death maintained constantly through training.