I wondered about that when I first read the article. A coyote kills for food. No coyote is going to kill and leave the food lying on the ground and wander off. Any adult coyote would be able to carry a BF away. They can be pretty casual about this when there is no serious threat to them.
That's right, that's something a stray dog would do. The little pup may have also have got into a scrap with some 'coons.