The fact that some people are stupid enough to think that they can safely drive when they are not looking at the road is utterly ridiculous.
It's not a black and white issue (driver attention). You aren't looking at the road when you blink; that's around
It sounds like this guy didn't have the situational awareness to see the cop; that gives me some evidence this drivers attention wasn't on the road enough. Other things besides tech toys can consume attention (I just caught my sig other cheating, or got an irritant behind my contact, got stung by a bee, was brushing my teeth or rehearsing for a meeting, etc etc). These activity specific laws are dumb; it's impossible to legislate everything that's 'stupid' to do while driving.
On the eighth day, God created FORTRAN.