I've witnessed lots of road rage incidents. Fortunately, none to date have involved accidents, injury, or gunfire.
When I see one developing I just fall back and watch.
Actually had a "chase" go right past me one day on US-2 while returning from the Monroe fair. Some "dim bulb" was trying to outrun a Deputy Sheriff in fairly heavy traffic. I commented to my wife when they came up from behind and passed us that "there's going to be an accident at the end of this chase". Sure enough, he exited US-2 at Hwy 9 and when he turned South, he became a "hood ornament" for a Northbound truck. I got to witness the Deputies administering a different form of "First Aid".
It sounds like the guy in the reported incident forgot to change the batteries for his brain before he left home. Either that or what Dave referred to as his "stupid gland" is an exceptionally large one.
Bad news is that under current conditions in Washington Department of Corrections, he'll be back to his own tricks in no time at all.