Auto Insurance Claims: road hazard, road hazard, regional manager

Question
A rock came off of a trailer of a commercial truck and hit my windshield.  I called the 1-800 number to contact the company and after many rotations was finally directed to the regional manager.  He claims (maybe rightly) that they are not responsible for the damage to my windshield because the rock is a road hazard.  

Is this correct?

Answer
Hi Sid,

If the vehicle was hauling rocks or gravel and one came off the back of the truck, they are responsible. However, if the rock  was on the road and was flung up by the trucks tires, then they are not responsible.

I hope this helps
Richard Hixenbaugh