From what I understand about the way things were at the house/farm, you're using the wrong analogy. I think it would be more likely: You have tools in your tool shed for employees to use for their work, and the key to the shed is left in a place where the employees could access them as need. Lizzie is only 13 so not allowed to use any of the sharp/power/dangerous tools, but takes your ax and kills everyone in her company owned house. Are you liable because it was your ax?
We have no way (right now) to know if CR had been given permission to drive the car, at least not by the owner, and I don't remember it ever being confirmed that the car was owned by the farm. It makes sense that he would have a vehicle or two for them to use to get around at work, run errands, get groceries and supplies, etc. , but it may have been understood (and possibly even stated) that only licensed drivers were to use it/them. With what we've been told so far, I don't feel you with your ax or the farm owner with his car would be liable. MOO