From the praire dogs and the size we see that was obviously a western coyote. Eastern coyotes are not so big. My over standard (read huge) GSD, Odin, killed three eastern coyotes when about a dozen of them jumped him four years ago when he was a 3 year old and just come into his prime. I wouldn't advocate it, but a GSD of sufficient size can hold their own easily with eastern coyotes even in a pack. A western could be handled one on one such as in this case. Remember, GSDs are far more prey driven than Labs are. A pack of westerns would likely be a problem though. A good reason (among many) to carry a gun out in the wilderness or the edge of it.
Yeah I can't see why the author kept refering to "the German Shepherd" either. That dog was no more than half GSD - if that much. Also, it appeared to be a good deal older than the Lab and past his fighting days. All-in-all an interesting sequence of pictures though.