he went down after the dunk. The dude basically jumped over a 7 footer. Look at the bulls bench reaction and that will tell you the story
What dunk are you watching? His waist doesn't get above Markkanen's neck. This happens all the time, someone goes for a big dunk and the defender tries to slide in for the charge. The defender gets knocked down by the dunk. Also, literally no one moves on the Bulls bench, so I'm not sure what you mean by that. But even if they did, I don't judge dunks on bench reactions. They react all the time, and the difference between a really good and truly great dunk aren't noticeable.
I'm just remembering that you're a big Nets fan, so I'll forgive your terrible take on this one.