As "plays that will result in you running until you puke" go, this one has to be right at the top. You simply can't make an incomplete pass signal as the receiver you were covering is streaking down the field with the football he definitely caught for a 40-yard gain. The definition of a tough scene.
I don't even understand how Malachi Ruffin thought this pass was incomplete. He looked like he was still trying to tackle the receiver for a second or so after the ball was caught and then he just ... let go. I don't know what he thought he saw hit the ground, but it obviously wasn't the ball.
I don't know how you line up against that receiver for the rest of the game after this. I'd ask to come out just to save myself the embarrassment.
This is why coaches tell you to always play until you hear a whistle, kids.