But that is not what slager claimed at all...he intially claimed he shot scott in “self defense”.
At the moment he decided to draw his gun and shoot Scott, it was in self-defense. Scott had fought with him and had grabbed his taser. But as he was drawing his gun the situation changed: Scott dropped the taser and started to run. Given this, he should have put the brakes on the action to shoot Scott. But instead he carried it through and shot him. It was his failure to stop the momentum of this action, which initially was justified but then quickly ceased to be, that led him to kill Scott.