I was halfway kidding about the “nick” part, but that is part of the deal. Unless you have to, you do not want to cut anyone in your way twice. By the time the light dawns that they have been cut, you have cut two more individuals and are perhaps 30 feet away and still moving through the crowd. You do not want a pause in the action by having to slow down.
If you see someone you do not want to cut, you quickly bypass them. Importantly, if you see someone being attacked, you may not be able to intercede if it is too far out of your way, because you have to get out of there.
And the media silence works both ways. Since they refuse to say that the mob was black, they are caught in a paradox by saying the knife wielder was not black. They might state his race, but with little other identification, unless it is caught on camera.
The authorities will also try to downplay even a dozen serious injuries, for several reasons.
Last but not least, if the knife wielder is identified, he can play the anti-race card, that it was a riotous black race mob, attacking non-blacks, and that you just wanted to get out of there instead of being savagely assaulted or murdered.
The authorities will not want to touch that with a ten foot pole.
Your post seems to be looking for a way to do violence and get by with it. That is not we are as conservatives or moral people. Violence should only be used to protect. To use a mob as an opportunity to knife people and get away with it is evil. If you were to do this, I would hope that you would be caught and prosecuted to the full extent of the law.