I'm going to take the high ground.
1) Veteran shouldn't of been on the phone while driving. In most cases this is illegal for a good reason, case in point. He's an idiot. Clearly he was distracted while driving and could've killed someone (possibly BMW guy)
2) Idiot BMW guy shouldn't of reacted that way, especially with your lady/baby in the car
3) Unfortunately the only conclusion out of this scenario is two fathers dead and two families widowed.
It's gonna be the unpopular opinion, mainly because of how it's worded, but you're right. I would venture a guess that it wasn't a hands free on the phone type thing because that's not going to physically distract you. Mentally sure.