Comment by toby-

It's common for older writers to insert two spaces after a full-stop. In fact, go through the cypherpunk mailing list (and many others) and you'll see it was the norm. As for Satoshi being British, he used predominantly British English but occasionally used American spellings and terms; it easily could've been intentional misdirection.

Adam Back doesn't write at all like Satoshi. Back's writings are filled with grammatical errors and he often makes spelling mistakes, which Satoshi seldom did.