Watch it again. That ball is pinned to his right leg after he gets both feet down. It stays pinned to his leg as his momentum carried him out of bounds. That is a tough call that could go either way.
Also, helmet to helmet contact is allowed in the NFL.
again wrong WHEN HE CATCHES the ball it is moving the whole time till it goes behind his leg by that time its secured hes on 1 foot and flying out of bounds. and no helmet to helmet is not allowed some 1 posted it was an illegal play try again.