the phrase "such a commission" refer to causing a road accident and killing the other driver.
the word a"manslaughter" can be replaced by homicide.
in paragraph 2, the writer compares the punishment of killing with weapons to killing while driving.
the writer is using Grant bell's case to support stronger penslties for drivers who cause death in a car accident.
the writer also thinks that the punishment foe all irresponsible driving at present is too mild.