I would say "the right call" based on A.R. 3-4-2-I. Isn't the CJ supposed to be on the ball to prevent the snap until team B is ready(ish)?
I went back to figure out what happened before that play, in case it was something really weird, but it looks like the previous play was an offside penalty on Ball State as well, and it looks like a dead ball foul. In that case, I'd agree with that AR being the situation at hand. After the administrative timeout for the penalty administration, they were not ready to play.
I was a wondering if it was something very bizarre like Ball State just expecting a timeout after a third down play, maybe it was an incomplete pass, but there was no stoppage at all. In that alternative scenario, with no administrative timeout, just a team forgetting that the play was still going on, would you still call delay of game, or could it escalate to illegal participation (non players on the field) or unsportsmanlike conduct in some sense?