There is no way Steve would be able to bring Carl back with Cardiopulmonary Resuscitation(CPR). When a person has gone into Cardiac Arrest, the heart has completely stopped. The only way to revive it is through Cardio Shock.
Carl is only hanging a couple feet off the ground, he could've just let go of the shelf.
Carl claims the beach ball can't go on the shelf because it can't hold any more weight. However, the beach ball fell from the shelf in the first place, meaning it was up there before, hence there is no sense in his argument.