That demonstrates that Japanese culture has the phrase. Not that Japanese culture has the phrase with the same meaning as Eliezer uses.

And even if Japanese culture has it, there's a difference between having it as a fictional thing and having it as a concept commonly applied to actual people.

Also, in this context, remember that fictional scenarios are often set up to have individuals drastically influence the result where real life scenarios do not. People like reading about Voldemort defeated by Harry Potter, not by 200 wizards doing routine policing misions that are thorough enough that they happen to find all the horcruxes, followed by massive military backup for the squad of identically trained men raiding his compound. That's why fictional characters often have something like tsuyoku naritai; it doesn't carry over to the real world.

By the way:

"Torah loses knowledge in every generation. Science gains knowledge with every generation. No matter where they started out, sooner or later science must surpass Torah."

Obviously Eliezer was not familiar with the concept "asymptote".