I'm sorry I presented them as mutually exclusive, you're correct that they are not.
The difference is that one is already illegal - stopped, as it were. I postulate that this law will not significantly reduce distracted driving, but that it will primarily serve to perpetuate our government's apparent war on privacy. To be clear: I'm perfectly fine with a warrant-based search, particularly of carrier records. All this law does is grant individual law enforcement officers yet more authority to judge and immediately punish.