Oh get te bollocksty fuck. That's the line pedalled by people who can't play football
I've put myself in between a player's run and the ball enough times, but there's a difference between holding your line and holding on to the player.
Pish - it's because football is incredibly precious and your average fan/pundit would get confused about the free kick being given 10 seconds after the foul, because they can't connect two thoughts if it's drawn on a fucking whiteboard. Ref: Jonathan Pearce "is it over the line, is it not over the line?!" meltdown.