What has Pokemon Go has got to do with this? The driver in question was playing Pokemon Go. He wasn't texting or doing some other action. He was Playing Pokemon Go. That makes Pokemon Go directly relevant to this incident.
It's cute to pretend that the details leading up to the accident aren't important and that the only important fact is that the driver is a fuckup, but doing so makes you a fool. We must recognize that the irresponsible behavior he was engaging in has a certain allure, that others are doing it, and that it is potentially harmful or fatal for both the participant and those around him.
Just because the driver is ultimately responsible for his actions doesn't mean we should ignore the circumstances that led him to make those poor choices. That would be short-sighted, irresponsible, and frankly dangerous.