Error on 2014 NFHS test

[WestCoaster]

Rule 10-4-7 clearly states that if you run the ball into the end zone, get fouled by B, then fumble in the end zone the basic spot is the goal line. This is exactly what happened in this play, is it not? I'm not questioning that this is a loose ball play! It is. But all the requirements of rule 10-4-7 have been met. The rule clearly states in THIS situation the basic spot for this foul is the goal line. What am I missing? What about rule 10-4-7 does not apply here? All conditions of this rule have been met. I'm clear on what is a loose ball play. This one example seems an exception to previous spot enforcement. Read the rule carefully and tell me how the play in this example is different.