The argument seems to try to deliberately obfuscate the issue. We generally think of an individual as knowing a language, whereas we wouldn't consider a non-conscious object (dictionary, translation program) to know a language, even if it contains much of the information. So we put the two together in order to produce an output that can only come from the two (the man on his own is not producing the output in Chinese), and then ask only about the man (because the idea of a book-man system knowing something or a book knowing something goes against the way we use the word "know").

It tries to intentionally confuse the reader in an effort to make up for a very weak argument.

A clearer example would be asking something like - does a company (the system) now how to make product X, when no individual in that company knows how to make product X (each individual knows only a small part of the production process)? Of course, a clearer example isn't used because it wouldn't elicit the desired response.