Lying may be too strong of a word. The users have pseudonyms; there was no reddit real names policy. It seems reasonable for multiple pseudonyms to be controlled by a single person.

Users may have been surprised to find out just how few other people actually existed. But I see this as legit. It would be like a big corporation hiring "Esprit Legal Firm" for their defense, winning in court, and hen finding out that the company was run by a single lawyer. Obviously businesses can't lie, but you're not required to list your own flaws either.