I've lived in Kansas City for about 15 years, and I've seen a gun get pulled on someone once. SUV almost clipped a motorcyclist while making a left turn into the lane a little ways in front of us. Motorcyclist did a quick u-turn, caught up to the SUV, and pulled a gun on the driver. The driver quickly and frantically apologized, the biker shook his head and reholstered his gun, and got back on his bike and both drove off in different directions.
I started slowing down to increase distance when I saw the motorcycle do its initial u-turn, but I was pretty much trapped in the lane. I had my whole family in the car with me - I'd have been willing to testify after, but no way I'd be willing to put them all at risk to intervene. I was looking for ways to get us to safety, and was pretty much down to popping us up on the sidewalk to get around and get away if things got bad (it was rush hour, there was no room in the other lanes for us).
What I see of the drivers in the video is a) It's early morning, and they're paying just enough attention not to hit each other in a rush hour crawl; and b) they're trapped by everyone else in the rush hour crawl. Not getting shot at this point (because you can't tell he's just targeting a CEO) means not getting noticed, because you don't have good options for getting away.
He could have done a number of other things. He wasn't just a cog, he actively drove many of the problems with the health insurance industry today, as the person in control of the most egregious offender.
I'm sure he'll be replaced with someone similar, and I'm sure he had plenty of encouragement; but that doesn't make him any less culpable.