Well see I work for an answering service and we deal with a lot of A/C technicians and what not and sometimes people will call to get their A/C fixed and the techs hop in the truck and go, then the person will call back and cancel the call, so I have to call them while they're on the road, the smart thing to do would be pull over and answer the call, but the companies would then get upset cause of wasted time if it was another person calling to get their A/C fixed, but if they drove all the way to the job and found out when they got there the call had been cancelled then that's more wasted time, so in that situation you're damned if you do, damned if you don't.
Again I'm still thinking this over just wanted to give you some food for thought.
I'd pull over every time, and if it cost me my job, then they'd get a nice lawsuit for trying to put my safety, as well as others, at risk and essentially forcing me to break the law.
I live in CT where cell phone use while driving is illegal. Not well enforced, though noteable, but still illegal.
No one forces me to put my safety in jeopardy, no one.