I don't think that buck was sick OR injured. I hunt one of the few areas left in Norcal that has a large deer population and I've come on coyote kill sites several times....I could tell from the torn up ground, ripped out hair and general gore what had happen and these incredible photos confirm my belief...It seemed to me looking at the sign that coyotes chase a deer until they can rip out a tendon or open the abdominal cavity and they it's just a matter of time (and extreme suffering for the deer)...
It is nature's way and I'm not one of those guys that says destroy all coyotes, but I won't feel bad dropping the hammer on them either. They know the score and they play for blood....
I've believed that coyotes are significant predators on deer for many years and what I see in those pics only confirms what I already thought to be the case....
Think about this kill from a statistics standpoint....A guy puts up a camera and it views a micro fraction of the habitat, yet it captures a coyote kill...For that to be the case how many deer got killed in other areas? 100's? 1,000's? This is yet more evidence that this sort of thing is probably pretty common...I would wager that we don't often find such kills because all evidence is gone within a few days...coyotes at night, buzzards during the day and before long not much is left save for the skull and some scattered bones that are soon covered in leaves and hidden from view....
The problem with a lot of game agencies these days in reference to biologists is that due to budget issues they don't get to spend ENOUGH time in the field. The field IS the lab, but our biologists are too often stuck behind a desk....Not their fault, just the reality of the system at this time...