nice objection,
the card should be 3/1 , 5/1 with a rule written on it : "at the end of the turn Ball Lightning has been summoned, deal 1 damage to Ball Lightninig"
but i don't see the change is going to happen
i suppose the official ruling is that a creature status (dead/alive) is checked after the creature is dealt damage or if his hp stats are negateviley modified (i personal prefere not to have such complex set of rules) or after the end of the turn