I'm not clear what you mean when you say "he identified as antifa" because it sounds like you're saying he identified as some member of some club called antifa. I've noticed that USA politicians often use this mythical "antifa" entity as a scapegoat and I fear you might have fallen into this usage pattern inadvertently?

As an anti fascist that uses to run black lives matter protests, whoever these antifa folks are they never invited me to their club!