The OP article said he was in the end zone. Watching the video I concur with you, however - it looks like the kid was out of the end zone when he caught the ball as well.
Watched it live. The catch was reviewed and he was in when he caught the ball. He was good by about 3 or 4 inches. I don’t care who won that game. I do find the decline in officiating disgusting where one bad call or no call determines who wins a hard fought game. The other bad no call was in the NC game when the quarterback was slapped on the side of his helmet as he passed out of his end zone. Ref standing right there looking at it threw a flag. It would have been a first down and out of the shadow of their own goal posts. After a discussion with the ref in the white hat the flag was picked up. It was replayed and replayed and even the sports casters were talking about how that was a clear penalty... slap to the helmet.