boo ... I had heard this statistic many years ago, as a sports writer in a NY newspaper actually timed the 'action' of a game.
As for penalties, this is why I laugh when I hear younger people - and even the (over)analysts on tv - say "so and so -usually the quarterback- is the best EVER ... 'back in the day' QBs took a beating, but not today ...
Granted, today's athletes are bigger, stronger, faster, and some serious injuries occur, but they don't get mauled and held the way they used to ...