It looks like Warren was handed the wrong card. Faye read it as Emma Stone for LaLa Land. It was supposed to be "Moonlight" as best picture. So it wasn't Warren and Faye's fault. They read the card they were given.
Yes, Warren was clearly confused when he saw that card in his hand. He just stood there and I am sure folks thought he was having a senior moment or something...then he handed it off to Faye and she also seemed befuddled for a moment and then just blurted out La La Land. Very awkward.