If there were two obvious places of "disturbance", I would definitely say it was not a poacher. A poacher would have no need to move the body from its originally downed position. This fact is supported by the location of the 2nd pile, next to a downed tree. I would bet that the predator ripped out the breast and ate on top of the log.

As to which predator...that's got me a little puzzled. Probably not a cat or dog, as they will target the entrails immediately after a fresh kill. I was first thinking an owl, just simply because they are one of the only predators that will not eat the entire carcass. Their beaks are also razor sharp, and excellent at removing just the breast meat. But considering you found it next to a downed log, that would indicate that the meal was most likely consumed during the day. Owls will carry their meals up to a roost, just for better vision and of course protection.

I would actually guess, possibly, a hawk of some sorts. Cooper's, and even Red-tails, can be quite large. The "holes" you found could be talon incisions, and this is the time of year when the females are fattening up to mate. Just a thought though...