let's slam another human's head into the boards like closing a car door shall we?
I don't see much force; he relents very quickly. It seems to me like he was trying to stop himself from slamming into the boards and unfortunately placed his hand on Nordstrom's head to brace himself. He brushes his hand off of Nordstrom's head before it hits the boards; he doesn't drive through. If it was intentional, he would have held his head and driven it into the boards. It doesn't look malicious.
The side angle, shown in the second half of the video, shows that he doesn't drive Nordstrom's head into the boards. He looks like he's trying to stop his own momentum; he reacts in a way that is harmful to Nordstrom but isn't motivated by a desire to hurt him.
The front angle is quite incriminating, but the side angle reveals where his hand actually is. That "push" seen in the front angle is actually his hand sliding up.
This is malicious.