Spoiling his story a bit, but the ex-Marine said the first guy fired 4 shots, everyone scattered, and he managed to ambush him from around a corner to disarm him. Said Antifatard didn't really seem to understand how the gun worked. The second disarm isn't obvious, but the Marine approached from the blind spot so he wasn't noticed until he was close enough to grab the rifle.
My own theory is these Antifa morons are the same radical left/liberals who spent years marching to ban assault rifles. Other than the JBCG/Redneck Revolt that teamed with Raz, these fuckers never encountered a rifle in their lives. They're just spoiled brats who want to destroy everything. They can coordinate a window smash or a mob beatdown, but they can't coordinate fire lines and holding down territory.
Antifa doesn't know what they're doing. The Marine did.