Speaking in terms of "items" hitting windows and who's at fault in regards to the highway...
If the item that caused the damage was witnessed to have come out of the truck in question, the truck owner is liable. If the item was kicked up off the road because of the truck, then nobody is responsible since it's an "act of god". In either case, your insurance company would pay under the comprehensive side of your policy and then, if warranted, go after the truck owner in example one, or nobody in example two.
One quick side note. If it's a rock that hits your windshield then there will bne no way to prove where it came from. Even if you are following a gravel truck that is fully loaded and no cover, it's going to be hard to prove anything.
Now, if a chair that they are hauling falls off and hits you then it's an entirely different story.
Yes and no. You could technically prove that the rock that hit your windshield was of the same exact makeup as those in the back of the truck using scientific means, but that may be a little costly
It really comes down to the other person trying to fight back if you say it was from their truck. In the end, your company would pay you and they'd go after the truck owner's insurance company via subrogation.
More than likely, if I sent a subrogation letter, I'd be told to fly a kite. It's not worth sending to arbitration. So, we'd probably have to let it drop.
If we did send it to arb then I've got a pretty good idea that we'd get shot down.
Speaking as a licensed insurance agent... (and the laws are still open to interpretation so this varies from state-to-state and by stingy agents and claims processors)
1. - The auto insurance company of the person who's property was damaged could "try" to deny the claim for "negligence" where they parked in an area known to be at high risk of causing injury to one's property. Most likely the company would just pay the claim minus the comprehensive deductible.
2. - Your homeowners insurance company "could" deny paying the claim for the third-party because of the above reason and because you may not have a rider covering damage to the property of others.
another similar situation happened to my brother-in- law's family...
My nephew tries to replay the golf commerical with a shopping cart in the parking lot...(these guys are good)....
He pushes the cart toward the cart rack trying to get it to roll in by itself, it goes off line scraps a car door....guess who was responsible and who had to pay, the 12 year old kid was not trying to scrap the car, but he had inherent responsibility...
Good Luck
Maybe play hard ball and the guy will not fight it , if he does I have a bad feeling you are out of luck..
another similar situation happened to my brother-in- law's family...
My nephew tries to replay the golf commerical with a shopping cart in the parking lot...(these guys are good)....
He pushes the cart toward the cart rack trying to get it to roll in by itself, it goes off line scraps a car door....guess who was responsible and who had to pay, the 12 year old kid was not trying to scrap the car, but he had inherent responsibility...
Good Luck
Maybe play hard ball and the guy will not fight it , if he does I have a bad feeling you are out of luck..
The cases out there all deal with people who were struck at a baseball game who sued the stadium or the city that owned the ballpark.
this issue is all about personal responsibility. common sense tells us that this is clearly not your (or your son's) fault, and certainly not your responsibility to pay for the windshield damage. Although I'm not a legal expert, it would be my guess that a court would side with common sense as well.
My suggestion is to call the man, simply explain that it was accidental and that he parked his car in harm's way. Tell him that you're not responsible for the damage and that you're not going to pay for his windshield and that's all there is to it. I would venture to bet that this would be the end to your problem.