What's really needed are things that have been happening in some US states; minimum penalties for being at-fault in collisions involving injury or death.
Doesn't matter if the driver was on the phone, or fiddling with the radio, or was just ignorant of right-of-way rules, and as a result, it doesn't matter what the cell phone records show or what excuse they give. If a driver is at fault in a collision resulting in injuries ... then there is a set minimum fine and a set minimum driver's license suspension period. I would add that in right-of-way-violation situations, the driver shouldn't just get their driver's license back after the suspension, they should be sent back to square one as if they were a new driver, and go through the whole testing procedure again (forces them - as best we can - to re-acquaint themselves with the rules).
Ideally, s. 172 should go away, and the penalties transferred to this.
Mandatory minimum sentences is one of those wonderful ideas that has so completely screwed up the American legal system. So much so that of course our own Federal Conservatives want to bring them here.
We don't need minimum sentences. What we need are appropriate sentencing guidelines.