It isn't just plebs though it is very skilled developers.
In a sense I respect the humility behind "I could see myself making this #ifdef error". But IMO it let's the CTO off cheap. This is exactly the type of obfuscation I would introduce if I were up to no good. This is exactly the plausible deniable I would manufacture.
Being real with myself: I could definitely see myself making a fatal error like this that got into an engineering sample lot but NEVER into production. I would lose sleep and probably come up with an empirical way to measure the entropy of seeds produced on the production line itself to detect just such an error.