Introducing a new food into a dog's diet has the potential for diarrhea, especially if the first introduction is a large amount. Even though you removed fat, there is still a lot of fat in the meat itself, so it may be a little harder on the tummy. That said, a lot of people use boiled chicken breast as a base for a whole food diet for their dogs, so the chicken isn't particularly bad in itself.
He may be allergic to chicken. But .. I warn you about giving your dog bones...especially chicken bones. They break and sliver very easily and are notorious for causing problems inside the digest tract of animals because they get embedded and stuck. It can actually cause your pet horrible pain due to severe blockage and may even be fatal.