The great thing about math is that it is scientific. If you think that a math proof is flawed, simply show the math that will falsify it.
Actually, no it is not. Math is a tool in science that can be used to give evidence, but it is not inherently scientific. A mathematical proof is not a scientific proof, as there is no such thing as scientific proof.
There's nothing wrong with the math in this piece. But it still fails to prove what it sets out to prove, because it fundamentally misunderstands the iterative nature of evolution. The failure is in the assumption that evolution is a completely random process. It is not. It has an element of randomness, but it is not completely random. Therefore, trying to calculate the "odds" of evolution producing anything is a worthless exercise.
The math is fine. The assumptions the math is based on are fundamentally flawed, insofar as they completely misrepresent how evolutionary processes actually work.
Is it? Math is just a tool. Math by itself is not scientific. It's only as good as the assumptions used to plug in the initial conditions, and the answers are the same.