Being able to make sound decisions and keep your cool under pressure are part of the job, and this was definitely a fail. I disagree that this agent should be assumed to be acting according to some prepared strategy, to go shoot all the Karens.
I also know that many of these protestors are experienced agitators and go out of their way to create these sort of situations, so that they have an excuse to protest and get good video material for the Social Media Outrage Machine. This situation escalated too quickly, so that they couldn't control it, and they all made a surprised face, but this is their (paid) hobby. They do this shit all day and it's usually fun for them.
ICE agents are an easy group to point fingers at, but they also attack firefighters, teachers, cops, nurses, ambulance personnel, bus drivers, trash collectors, etc. It's getting harder and harder to hire for essential services, and to retain staff, in urban areas, as you end up constantly under attack. Islamists, Marxists, environmentalists, illegal immigrants, radical feminists, Transactivists, Antifa...
It's all the same club and I am not in it.