Spot on analysis and excellent catch with the people in the wings acting as blockers. Those blocking tactics are used a lot by antifa; in most affinity groups there will be people whose main role is to swarm and block; you can see it very clearly, for example, in a lot of livestreams where they want to impede any recording.

It says so much about the patriots' basic goodness and respect that the provocateurs were not able to lead the group into action, that everyone turned against them immediately. It's really easy to rile up a crowd that big and full of adrenaline. But they saw the glass being broken and that flag being repeatedly smashed and the "fuck antifa" chant went up, loudly, and patriots put themselves between the guys and the doorway. And yet they are being called terrorists and put on no-fly lists.

I've had a lot of experiences with protest dynamics, and I've honestly never seen a crowd this size be this disciplined in its actions.