There is no doubt that coyotes CAN take down adult deer, however, I do not believe it is that common. Much of the research that says coyotes only take fawns, actually says that their highest predation rate is on fawns. Bobcats are much more of a problem in my book. I have seen coyotes just out walking around and go right through deer without the deer even being bothered. However, EVERY time I have seen a cat in the field, the deer freak out and often try to run the cat out of the field.
I have a few thoughts on the pics though. It is August in OK so it could be a buck facing heat exhaustion. The buck could've been run there from somewhere else and already close to giving up. Something about the deer doesn't seem right to me either, something about the body and head seems off but I can't place it.
However, there is no doubt that anyone wanting to strictly manage their deer and increase their numbers/reproductive success needs to participating in predator management. Predators need to be managed like anything else. Wolves, coyotes, bobcats, and birds of prey all need to be kept within certain numbers and as long as they are, there is no true harm to the other wildlife (in an ecosystem type of sense)