The press secretary for the Presidential Property Management Department certainly wouldn't lie, of course.
source I suggest we assume that this video shows none other than Mr. Vladimir Kozhin himself.
The whole point is that the magical sounds of the siren and the "quacker" (a colloquial term for a loud official car horn) return him to his true form—that of a dog. Which is why "a large animal sprawled across the back seat" should really be read as "a Category A official in the performance of his duties".