Also, a reminder that 'undercover antifa' is just as bullshit as 'Russian influence operations', as an explanation for why this sort of thing blows up so violently.
If you have a healthy movement that does not condone violence, a small number of outside agitators cannot provoke riots, because they will simply be ejected from the demo. A spark does not cause such a fire when there is no fuel.
They rioted because that's what they planned, intended, and wanted to do.
They rioted because fascism and white supremacy is inherently violent.
The 'antifa' accusation is projection, as usual.