The thing that's most distinct about black people in these moments is their fight or flight response. I think many white people see this and think it's foolish for the black man to make that choice because there would be a low probability of getting away and it would just make the situation worse. It could be dangerous, or it would just be more expensive legal hassle from this, our White brains think.
The reality is, that black was not thinking about running to the window and jumping out at all. That was all just pure animal instinct. There was no strategy to what would happen after he pulled away from the cop. White people make choices in those instances, sometimes good, sometimes bad. Blacks resort back to a primordial response.
When the White cop says "don't tense up." The cop knows. He knows he's dealing with a force of nature.