That doesn't mean that what he was doing was bad (or good), but the assumption that anyone Japanese must have sword training is...mistaken, IMO.
You're being kind. Mistaken is a very nice word to be using here.
Graham -- look up the Haitorei Edict of 1876. That was 136 years ago. Heck, back in the 1930's it was still almost 60 years... Sword training, sword making, sword crafts nearly died out during Meiji. It was a niche thing at best as Japan was modernizing. And WWII almost killed it completely.