This is exactly the sort of pedantic cluelessness that scientists are seeking to avoid by not publishing their code.
To paraphrase what the other developer said: "I don't want my work to be checked, I'm not here for accuracy, just the act of doing science".
When I was young, the ability to invalidate was the core aspect of science, but apparently that's changed over the years.
This is exactly the sort of pedantic cluelessness that scientists are seeking to avoid by not publishing their code.