Earlier quoted context omitted.
I agree it isn't really proof by contradiction. It is more like proof by demonstration of concrete failures in real life demonstrations, which is stronger. It is like the author is saying 12 is a prime number and I am like but I divided it by 2 just the other day.
Nit pick, but proof by contradiction is necessarily stronger as it is deductive reasoning, and this kind of "proof" by anecdotal evidence doesn't rise above abductive reasoning. Still useful, very much not a proof.
Empirical facts are the strongest thing we have in this domain.