Here we see the defender immobilized the attacker but at the same time he has remained static himself.In a case the perpetrator has accomplices our defender is vulnerable to an attack.Also with this technique he does not control the hands of the opponent who if he is armed with a knife or other sharp object can easily stab him.Here is a violated basic rule of self-defense: "Never stand still and never put yourself to a dead end."
Here the defender got a grip on the perp's gun but he doesn't move the muzzle away .He is still in the line of fire. His concern is to punch the bad guy in the face. Wrong! Fatal mistake!
He is attempting to disarm the perp and the pistol's muzzle is pointing at his face at the same time the perp's other hand is free to attack him. Avoid it!!!