In the scene where Red and Andy are talking about the rockhammer, Floyd, Heywood, Skeets, and Red and playing catch. Red catches the ball twice without ever throwing it back.
I noticed that also, but if I remember correctly, you don't actually see Red the entire time, so I figured that while the camera wasn't on him, he threw the ball back.
I understand he could have thrown the ball back when the camera wasn't on him, but I don't ever remember hearing him throw it back. Every other time you've been able to hear the other in-mates catching the ball. I really think this is at the very least a sound screw up.
I watch this movie every night and I have studied this scene carefully. Being a ball player myself, I know it is impossible for Red to have thrown the ball back. If you notice the way Red throws he twists his whole body. When the camera is not on his face it is still on his torso and chest. He doesn't move. He could not have thrown the ball.