When Drivers Kill

I've often thought to myself over the years that if I ever wanted to kill someone the best way to do it would be to drive over them. I would wait until I found them stepping into a crosswalk and make sure that I hit them while I was turning onto the street they were crossing. I would then screech to a halt, return and scream "Oh no, I didn't see them, I'm sorry!" If I planned it just right, I might get away with a traffic ticket and have my insurer pay the bills.
Of course I'm being facetious but the thought ran through my mind again this evening when I was watching the news. A road rage driver had run someone off the road and then returned and succeeded in driving over and killing one of the vehicle occupants after they had exited their vehicle and stood on the shoulder of the road. The question posed by someone close to the deceased was why hadn't the driver been charged with homicide?
The Criminal Code of Canada says that homicide occurs when someone directly or indirectly, by any means, causes the death of a human being. Homicide is not an offence unless it is culpable, meaning that the death is caused by an unlawful act, criminal negligence, causing someone to kill themselves by threats, fear of violence or deception or wilfully frightening them, in the case of a child or sick person.
Murder is culpable homicide where the person who causes the death of a human being means to cause his death or means to cause him bodily harm that he knows is likely to cause his death, and is reckless whether death ensues or not. However, murder may be reduced to manslaughter if the person who committed it did so in the heat of passion caused by sudden provocation.
The driver in this story was charged with criminal negligence in the operation of a motor vehicle causing death. The maximum penalty here is the same as it is for murder, life in prison. The main difference is that the minimum sentence imposed by each of these offences is different. The choice of which charges to prefer belongs to Crown Counsel after looking at all the evidence in the context of current case law and having decided on whether there is a substantial possibility of conviction.
Reference Link: http://www.drivesmartbc.ca/viewpoint/when-drivers-kill