The NFL official rules very clearly state that it was NOT a facemask penalty:
"Article 5 No player shall twist, turn, or pull the facemask of an opponent in any direction.
"Penalty: For twisting, turning, or pulling the mask: Loss of 15 yards. A personal foul. The player may be disqualified if the action is judged by the official(s) to be of a flagrant nature.
"A.R. 12.12 Third-and-10 on A30. Runner A1 runs to the A33, where he is tackled by B1, who incidentally grasps A1’s facemask on the tackle, but it is not a twist, turn, or pull.
"Ruling: A’s ball, fourth-and-seven, on A33. No Foul."
The game was over and the Lions won.