NFL Facemask Enforcement

[chymechowder]

In the bears lions game tonight. Bears ball at their 20. Cutler gets sacked at the 17 but the Lions had grabbed his facemask.  Next play was at the 32.

I'm thinking it was an oversight. But maybe the NFL doesn't enforce this from the previous spot?

[APG]

Rule 14, Section 1

FOUL ON RUNNING PLAY WITH NO CHANGE OF POSSESSION

Article 12 When a foul occurs during a running play (3-27-2) and the run in which the foul occurs is not followed by a change of team possession during the down, the spot of enforcement is the spot where the ball is dead.

Exception:

DEFENSIVE FOUL BEHIND LINE

(7) When the spot of a foul by the defense is behind the line of scrimmage and the ball becomes dead behind the line, enforcement is from the spot of the foul or the spot where the ball is dead, whichever is more advantageous to the offense. If such foul incurs a penalty that results in the offended team being short of the line, the ball will be advanced to the previous spot and no additional yardage assessed.