Maybe the driver lost his head in this dispute, decided not to guess what was about to happen, and used his weapon to inflict a non-lethal wound which ended the dispute.
Was the driver justified?
Are you one of those people who act irrationally and then excuse themselves by saying, "I just got angry and lost my temper", as if that justifies what you have done?
Maybe you think the driver should have waited until the cyclist killed him before taking action.