also, his body could've gone into shock, stopping him from screaming. Sure, he might be able to scream right as it started, but it would stop after a few seconds.
WHY DOES THE SPRINGLOCK AUDIO HAVE WILLIAM AFTON SCREAMING? BECAUSE HE WAS IN INTENSE PAIN. BUT HIS VOCAL CORDS WERE PUNCTURED, NOT TO MENTION HIS LUNGS FILLED UP WITH BLOOD. SO HOW IS IT POSSIBLE?