Can someone explain a call (NCAA)?

[SamG]

I'm speaking as a fan who admits not knowing the rules, and what the talking heads said didn't make sense either, so I figured you guys could possibly explain things (pardon me if I don't get the right terms)...

Team A has 4th down on it's own 30. They snap the ball, the punter puts his foot to it, and the ball hits A76 on ~32 who's engaged with a B player. The ball ricochets off (hits no one else), stops on the 39 and a (different) B player falls on the ball.

The WH turns on his mic and says since the ball hit A76 in the expanded neutral zone, it will be 1st & 10 for B on the 39. The talking head said if A76 had been in the neutral zone when hit by the ball, the ball would be dead right there.

So two questions...
1) What is the 'expanded neutral zone'?
2) Why is the call different based on where A76 is (obviously that's what the rule is, but is there any reasoning behind the rule)?

Thank you in advance.