Are you talking about the time when there was a Birmingham player down injured and the referee stopped play when Ruddy was in possession?
That was a perfectly acceptable decision and one of the kind you see every week. Actually, I've noticed that with the new, uncontested drop ball law, referees in general seem slightly more inclined to stop play for injuries, knowing that the ball is just going to go back to the team that was in possession (or the goalkeeper if the ball is in the penalty area, as it was in this case).
There's no requirement for the ball to be put out of play before the referee stops play for an injury.