If I was a busy decision maker at a major Japanese firm with a dozen direct reports and a hundred balls in the air simultaneously, and if I could even spot translation issues in a few minutes on the polished demo presented to upper management, then there's no way I would ever assume anything is correct with the software when I'm not looking.

Let alone my subordinate's subordinate's subordinate who would actually be using the software day in day out with their job on the line.

So it's a very sensible heuristic. If it's supposed to be a serious enterprise software product, offered for sale in Japan, then spending a few million dollars to hire expert technical translators to double check everything should not be an issue.