the law is not about the words you argue. there are certain elements you must meet for each charge and you as a prosecutor must prove beyond reasonable doubt. you can't make arguments as gun's purpose is to kill. because that's not enough and not beyond reasonable doubt. Guns can be used to threaten , or to cause injury or to kill a prey. or in defense. you have to prove the intent to kill (which is an element of attempted murder). pointing a gun at someone's head is an evidence . but not enough, you need more than that. I don't know the details of this case, it might be possible. Though assault with a deadly weapon is a felony and easier to prove in cases where attempted murder is harder.