Exactly. In this situation, the people on the road have less information that we do after the fact. People deserve to know if they were put in danger and why. Since this was done on a public highway, anyone that uses public highways has a right to feel upset about the behavior.

I would like to think that a call to 911 with more information (which of course a fellow driver wouldn't have) would be handled differently:

  911: 911, What's your emergency?
  Driver: Hi, someone on the freeway has purposefully disabled their vehicle in a location without shoulders, and is slowing while driving, impeding traffic.  I'm not sure if the power brakes or steering are functioning, but the driver is definitely not in full control of the vehicle.
  911: We've dispatched an officer to your location.  Has there been an accident yet?  Has the driver recovered control of the vehicle?