Here’s my take.
I do not like seeing young men getting shot either.
The cop in Wisconsin, if he believed an assault was going on, may not have been wrong to go in alone. Just because someone says he is 30 seconds away, does not mean it is so. Things happen, cars make wrong turns, drivers get lost, etc. Meanwhile there was an assault victim who might have gotten killed while the cop was waiting. So, while the back up may have been close, I do not fault the cop for not waiting.
What I see as an unintended consequence of the whole “hands up don’t shoot, all cops are racist” narrative is that it encourages young black men to think it is okay to resist cops. (Now, I bet this particular young man was probably not thinking too clearly, adrenaline and maybe other stuff), but this media narrative has its own dangers, if it encourages young people to decline to cooperate with the police. If a cop is wring, take it up with his boss the next day. Video will help this process so film the cop. “Do not assault a police officer. Ever.” That narrative needs to replace the “Hands up. Don’t shoot” narrative if we want to save young black men’s lives.
By the way, a young African-American woman in Ferguson has come forward to the cops and told them that she was a witness to the Brown shooting and verified that Brown did not have his hands up when he was headed toward the cop, but she declined to come forward immediately after the incident because what she would have said would have contradicted the media narrative, so she kept quiet. I think that says a lot about the media in the US: “Don’t confuse me with the facts. We have a narrative going here! Reality cannot be allowed to contradict the narrative!”