It would not have hit him in the shoulder. He had to reach behind him completely to make a play on it. You people need to stop letting announcers sell you on stuff you desperately want to believe and actually look at what happened. I have the tape. Cooper had just come out of his break and was running almost parallel to the yard lines when the ball went behind him and he had to reach back against where he was running. Look at how huge the separation was and the error was THAT much?
If Dak was going to float the ball more, fine. He even had room to do that. But you can't rifle the ball there and expect a WR to compensate for an error that egregious that fast. It needs to be on target in that case. QBs talk about trusting a receiver to be where he's supposed to be but receivers trust that QBs are going to have a ball not be off by multiple feet while running top speed.