In the expanded hypothetical that Harlan actually gets in the way of the play and causes a different outcome, the ref could have awarded a touchdown. But as it stands the flag that was thrown was for him being on the field and arguing with the ref, that in and of itself would not have called the play back and would have been considered a dead ball penalty.
My whole point is just trying to clear up that even though it happened during a live ball, in this case it was still considered a dead ball penalty.