You captured the facts of the particular case quite well.
The most salient part is that the person sending the text must "have reasonable knowledge" that the person receiving the texts is driving. For a
driver either to read texts or

to
send texts is just absurd.
I wonder though if this also becomes precedent for making a phone call to someone while you know they are driving? It's not illegal to talk on your cell phone while driving in some states, and in other states it is not illegal to talk on a hands-free cell phone while you are driving while it is illegal to talk on a hand-held cell phone while driving.
Given the way that I've seen some drivers waving their hands around while driving (one infers they are gesturing while talking on the phone), and given studies that show how it's the act of talking itself that distracts the driver, I'd just as soon no one talk on the phone at all while driving, especially if it's an argument.