It is perfectly normal for Riley to eat the bones, it should be fine. On rare occasions a part of the bone can become lodge in the stomach or intestines and cause a blockage, requiring surgery. signs to look out for are innapetance, lethargy, vomiting, diarrhoea or constipation. once he has finished eating you really should remove all left overs especially if you feed him outside, a bone that gets left in the sun is just like a cooked bone and can splinter and cause damage to the mouth and insides if swallowed. if there is meat left on the bone it can rot and make riley sick.
enjoy the nice breath!