1. Since his example (the fall of the Berlin Wall) is a one time event without any historical data and can only happen once, it's glorified guessing.
2. He ignores that a bell curve is specifically for results that have very predictable ranges. In Black Swan, Taleb calls this "Mediocristan" because the range of height of adult human males holds roughly to a predictable range aka we don't run into men who are 6 inches or 10 feet tall.
3. By taking this once in a lifetime event and applying a bell curve to it - as if the existence Berlin Wall was a gaussian event - he's trying to make guessing look like science.
4. After declaring it "proven", he goes on to compare it to another one time event.. then end of human life.
If he was talking about a regular event with historical data, this may be useful analysis but as is.. oh, he's selling a book. Got it.