I completely agree with Majestic-san. Even though 常 isn't there, the meaning doesn't change. Plus, 無為而無不為 is a famous maxim that is also used in other chapters, so his memory would be faulty, I assume.
Yeah, it's also impressive that he was 秋山真之's contemporary at the Naval Academy.
I've read 海と毒薬 by 遠藤周作...