Im pretty sure they could have just handcuffed him and taken him away in that case. The conveniently camera-blocking humvee and the fact that this happened so fast kinda tell me this isn't your everyday arrest. Just gonna quote a tweet from the article
I know I'm late, but you're not required to be read your rights the second they arrest you. They can read it to you once you get to a booking station/whatever, which was not shown. There really was nothing unusual going on. They probably called the vehicle to take him away in advance because he was out past curfew, and then took him to a booking/police station.
However, I have heard that some people have been held for more than 24 hours with no charges, and inside extremely cramped cells full with people. That is not acceptable.