Answer:
If Nathan's additional injuries were severe, then Sam is probably liable for negligence.
Explanation:
There is no law that forces someone to help another person in peril, you have the legal obligation to call for help (usually 911), but your obligation ends there. If you decide to help someone, then you are responsible for that person's well being and must exercise reasonable care. Even if you are not a properly trained rescuer, you have the obligation to not make the victim worse. If Nathan's health suffered due to Sm's negligence, then Sam is liable to him.
This is a reason why you have to think twice before assisting someone in peril since once you decide to be a rescuer, then you are liable for any bad consequences that may occur. For example, if you are trying to help someone out of a car after an accident, an that person's leg or arm is broken in the process, then you may be liable for it.
