The M1911 series pistol requires one more action to fire than a double-action pistol, which is critical.
The need for one more action means a slightly delayed firing time, and given the presence of six guards, Gao Yang believed it was unnecessary for the guards with 1911s to risk a discharge by keeping a round chambered at all times, especially critical. Had it not been for this, Gao Yang wouldn't dare to make the person with the 1911 the last target and turn his back on him.
As it turned out, Gao Yang's gamble paid off; he didn't suffer any shooting from behind before he turned to aim his gun at the sixth person.
But once Gao Yang turned around, his last opponent fired.
Gao Yang fired at his last opponent, and his opponent also fired at his head.
Gao Yang's gun rang out, and he clearly saw a small hole appear in his opponent's left cheek, then a bloody hole burst open just below the ear on the right cheek, but his opponent only jerked his head violently and didn't fall.