My guess is it had a little help and was forced to look so uncomfortable by some "control" or "grasping" by that players hand.

In a fast paced game though without a clear view of him actually grasping the face mask it leaves some acceptable room for it to have been missed. Unless they start allowing instant replay, slow motion or still photos during games to call/enforce penalties (outside of auto reviews of targeting penalties) we can't really expect that to always be called in these scenarios...