When Bugs slides by the Champ and punches him while he has his feet soaked in oil he is wearing boxing gloves, but when he goes to the other side of him a few seconds later he is back to wearing his usual white gloves.
Bugs describes a 'rabbit punch to the kidneys' - a rabbit punch is to the back of the neck or skull. The term is derived from a technique hunters used to kill rabbits quickly, by the use of a sharp chop to the back of the head where it meets the neck.