Disagree. This line of thinking leads to the fragile "provably safe" design strategy.

History of engineering tells us that provably safe, provably secure systems aren't, because even if your proof is mathematically correct, you most likely forgot to include some relevant aspect in your model, which leads to an exploit.
In real-world safety and security engineering, you don't want to rely on a single-point-of-failure design, you want to think about exploits and faults, both to provide defence in depth and to use them to stimulate your intuition about the mathematical models you use, reducing the chances that you miss something important.