Please clarify a call

[kidclutch]

First off I'm not a football official - any insight from the pros on this particular penalty assessment would be helpful.

While watching NCAA football this past weekend I recall a ruling that I was not aware of:
Team A has 2nd &12 and attempts a pass that falls incomplete. During the play a Team B player is flagged for a 5yd minor face-mask against the QB.

The white cap's call is for a 5 yard markoff from the previous spot and "due to the ball crossing the line 'o scrimmage" - it was an automatic first down. I thought it would have been 2nd & 7. Any clarification is greatly appreciated. Thanks in advance.