I agree that one has to be cautious... and a heads up might have been nice, and if shouted, might even have woken the driver from their stupor...

But let's face it... motorists have a tendency to not convey intent... nice new cars with nice bright blinky lights and yet the driver could not avail themselves to flip that easy to reach switch... com'on. Motorists want cyclists to be predictable... well folks it is a two way street... how about a little predictability from the driving set... USE THE DAMN TURN SIGNALS.

About a week or so ago someone mentioned that drivers could be ticketed for failing to signal... really? They sure don't act like it.