No that's not a mistake. I'd say all of the following constructions are synonymous and deal with nationalities:
Russians like to drink vodka.
The Russians like to drink vodka.
The Russian likes to drink vodka.
That last one, the usage you are wondering about--it's a little bit old-fashioned, maybe. And I think that it's mostly used for European nationalities. Can't remember ever reading "The Canadian".
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