The 9mm pistol rounds fell short in instantly incapacitating a person unless they hit a particularly lethal spot.
So when Yang Yi realized his shot didn't immediately render the enemy incapable of movement, his instinctive response was to lunge to the side as quickly as possible.
The scene played out like this.
Yang Yi fired at a man's forehead at point-blank range with his gun, then turned and shot another person in the chest inside the bedroom. As he fired, his body tilted right and fell to one side because the person he hit merely staggered but didn't fall.
The sound of gunfire echoed once more as Yang Yi, now on the ground, crawled forward hastily because the wall wasn't load-bearing and could be penetrated by AK74 bullets.
Yang Yi crawled a good distance before turning his head to see the bullet holes climbing higher up the wall, indicating the shooter's difficulty in controlling the muzzle rise, until the shots struck the ceiling.