Check the video again. It's Kevin Casey being loaded into the ambulance, you can tell by the facial hair since Hester and Hall's is non-existant(the same video is in the Season 17 preview video). Also, when Sonnen jumps up to run into the cage, one of his coaches claps his hands like he's satisfied with what happens. My guess is Casey and Hall fight later in the season and Hall destroys Cella.
they said next episode clearly so no its hall or cella and im ebtting cella gets his clock cleaned