Assuming this is a 7-man crew (I didn't see a B in the video), this player is the B's key. When the hit occurs, the pass has just been caught. If the officials are going with the coverage of "man, zone, ball", they have all switched to the pass and these players are no longer being watched/keyed on. I'm afraid this might be a situation where one official sees a hit out of the corner of his eye, but he isn't sure of exactly what happened.
This would definitely be a great opportunity for the conference to review the play and take action after the fact.