JMO
I agree. Its basically the definition of negligence. Something happens and sure you didnt expect it but you could be negligent for allowing the circumstances that it happened in the first place.
The bottom line is a civil case jury will decide. Thats why there are so many civil cases. Some won and some lost.
The link below is mostly talking about car accidents and negligence resulting from it but in a murder case where an illegal driver is on the road and a murder happens with a possibly company owned vehicle it could get real interesting in this case.
"Negligence can result in all types of accidents causing physical and/or property damage,
but can also include business errors"
"
Nine states (California, New York, Michigan, Florida, Idaho,
Iowa, Minnesota, Nevada, Rhode Island)
make the owner of the vehicle responsible for all damages caused by a driver given permission to use the car"
Legal Dictionary - Law.com