It looks like purebred GSD to me. Coyotes *can* be bigger, at least here, they can be up to 70lbs. But that is all dog, and looks all GSD to my uneducated eyes. I see them all the time here. In fact, they were just howling a victory kill about 20 minutes ago across the road.
Wow! And we're almost neighbors. Coyotes in my area are probably 30-55 lbs. catch them on my trail cam a lot. They like our property for some reason. Anyway, so it is possible to make a larger hybrid with those larger coyotes it appears. Still shepherdmom, IMO all I see is GSD.