Seems fair to me.
In 2009, during my senior year in high school, my entire table had their cell phones out. All saw the teacher coming except me. I was busted having it out and she took it.
I gave her the phone.
Why? Because I wasn't supposed to have it out in the first place, and I had to pay the consequences for doing so.
Did it suck my buddies weren't caught? Sure. But I'm not blaming them, and I'm not blaming her for not catching them.
Why?
Because I am responsible for my own actions, and pay for my actions.
So if I follow your logic, you would say that since this cop was caught using excessive force he should man up and receive the consequences for his actions; however, if no one videotaped the event he should get off scot free. Correct?