I get that if he catches it with both feet while already in the end zone. That is, a receiver established position first. But when out of the end zone (or partially anyway, as he was, he only had ONE foot in the end zone) I thought (and even if wrong, still think) the ball should have to break the plane.
On reviewing a better angle (how did they not have it during the game??) looks like he crossed the plane with the ball easily--there is a very clear shot of it from behind. For whatever reason during broadcast they kept showing that weird diagonal shot. Was driving me nuts.