I agree but law enforcers are the professionals
They are also human and have human emotions and responses.
From the presented evidence it is certain that the original, physical confrontation took place while Officer Wilson was INSIDE the police car. It is obvious that he was punched several times. Any reasonable person would be in real fear for his life, and or safety, under those circumstances.
That is not to say that the officer handled the original contact properly, he may or may not have. We do know that the adult who was unarmed and shot, had just make a choice to rob a store and attempt to do physical harm to someone in that store when they tried to stop him.
It is more than reasonable to assume that IF he had not robbed the store, and IF he was NOT walking in the middle of the road, he likely not have been approached by Officer Wilson in the first place.