Your question was referring to charging an individual directly responsible for the crime. It's not a relevant example to this case, where they are dragging third parties into it, who are responsible by proxy.
As to your question, it would depend on how much emphasis the state puts on distracted driving. If using your phone while behind the wheel isn't illegal in that area, then you're at the very least, gonna have a decent defense that your actions leading up to the crash weren't illegal, and thus not relevant to whatever higher crime they're potentially trying to charge you with.