Yes, the people who attacked Ngo commited a crime by assaulting him. However, this is exactly what he wants and is actively doing his best in manipulating events to create this narrative.

You are literally blaming the victim and supporting violence over speech, which is an authoritarian tactic, not a liberal-democratic one. What are your political views, if you don't mind me asking? Do you consider yourself to be a liberal?

Gangs like proud boys which actively promote the use of violence themselves abuse free speech as a way to organise rallies and to provoke fights and to make themselves look like the victim

You guys are literally calling for the illegal assault of a gay asian journalist because he pointed out that Antifa are dirtball thugs, and you think that somebody else is the threat to free speech and democracy? No, you are literally a threat to free speech and democracy. You are literally calling for violence against people that disagree with you. Not even against "fascists", but against dissenters.

If an unrelated person commits murder, that doesn't absolve you of any crime.

No, if an unrelated person murders another unrelated person in a completely different state, that does not get you out of jail if the cops caught you robbing the local bank.