Correcting mis-set LTG equipment (Sam Houston State vs Mont State)

[jchamp]

Situation:
3rd quarter, about 10 minutes. Montana State is driving and gets a first down at about the Houston 16. In the subsequent play, defensive holding is called and enforced half the distance, to the 8 yard line, but the LTG is reset on the sideline, and the TV crew even puts "1st & Goal" on the screen. The subsequent play gains about 3-4 yards, beyond the "correct" LTG. After this play, the officials conference and the Referee announces that the foul was not an automatic first down and that the result of the play would have resulted in A reaching the correct LTG, therefore the succeeding play would be 1st & Goal. MSU then scored on the 1st & Goal play.

My question:
Is this the proper way to handle (in the various levels) the discovery of an error in the LTG equipment? When is it too late to correct the LTG equipment?