I've literally never heard about it before
You've never wondered why players don't just dribble the ball from a free kick/corner?!
I would have assumed the first touch would have been the actual kick. Granted, you don't often/never see people take a free kick in two touches, but I didn't know it wasn't allowed. Even if that rule actually exists, surely that was a foul by Hart so how it bailed him out in the end and he got to retake it I will never know..