I don't see this as a question of joint possession. It looks to me as if the Bronco receiver had the ball in his grasp and it was wrestled away from him by the Bengal defensive back. The DB has possession in the field of play before he goes out of bounds so it's an interception (if you don't believe the receiver ever possessed it) or a fumble with recovery by the defense (if the receiver possessed it and lost it to the DB). Either way, it's Bengal's ball. I would rule the same in NCAA.