At the 11 and 12 second interval it appears that Kyle’s gun has jammed due to the attack on him (falling, kick from one guy, and hit by the skateboard by another). That is when the now one-armed guy decides he has the chance to kill Kyle. The attacker was raising his hands and backing away, and then suddenly moves in with gun pointed at Kyle.
Kyle quickly clears the jam and defends himself.
A video from another angle shows Kyle getting up after shooting his attacker, with his rifle at low-ready. He begins scanning the area and sees the guy in black armed with a baseball bat. The baseball bat lowers his bat and shrugs - and Kyle continues his scan and then jogs off.
Pretty impressive for a 17-year old.
Certainly seems to know proper use of a firearm, unlike Master(bater) Jay and his bunch, who are more deadly to themselves than to potential enemies.