Causation in Tort Law

Standard tort law requires the plaintiff to prove a defendant or defendants acted negligently, were the proximate cause of the injury, and that there actually was injury. Failing to do all three is grounds for dismissal.

So, for example, I go speeding by your house at three times the speed limit (negligence), which causes you to exit your front door to yell at me and proceed to stumble down your steps, breaking many bones and causing internal injuries (damages). The question is: Did I cause your injury. A legitimate court would answer no.
If I drove directly into your house, and the force of my car, either directly or from flying debris, caused these same damages to you, then yes, I caused your injury. But the fact that you chose to exit your door to yell at me does not constitute causation of your damages by me.

Similarly, let's say that after a class I delay a student's departure from my classroom to discuss his performance at a recent baseball game. After ten minutes he leaves my classroom and, while walking to his next class, is struck by lightning, which causes serious injury to him. My action (delaying him) did not cause his injuries. Consider the counter factual: What if my delaying the student caused him to miss the thunderstorm that killed two of his classmates who left right after class. Does this student owe me for saving his life?

Although this is a criminal case rather than a tort, the same reasoning should apply.

KSDK - If it hadn't been for Massigh Stallman, Missouri Highway Patrol Trooper Ralph Tatoian would still be alive, and Stallman is responsible for his death, a jury has ruled.

In April of 2005, Trooper Tatoian was driving on Interstate 44 to the scene were police were looking for Stallman, a wooded area in Gasconade County. As he drove with his lights and siren on, he came over a hill near Pacific, and slammed into a tractor trailer. Trooper Tatoian was killed.

What if instead of having been killed in an accident while racing to the scene of the manhunt, Trooper Tatoian avoided being part of a fatal shootout where he would have been had he not received the call to proceed to the manhunt. Would Stallman have received a lighter sentence for saving the trooper's life?