Grossman is a bright guy and his analogy is good up to a point. It does not; however, account for the sheep dogs that become rabid. They are in some respects, more dangerous than the wolves because they are already moving in and amongst the sheep with impunity, authority and the veil of legitimacy.
Other than the perpetrator who beat up a policeman and then desired to return and beat him some more, no one else was shot or killed by the police. All the other shots came from the rioters, themselves, most of whom were not even from Ferguson.