When a keeper is playing the ball within the six second rule then the ball never left play for it to have to come back into play. It only applies when the ball has left play. Nothing can happen when the ball is out of play apart from yellow and red cards. It's like if the ball is out of play for a corner, if a defender thumps a forward while they are waiting for the ball to come into play, then the defender still gets a red card but it is not a penalty, it's still just a corner. In the Joe Hart incident then the ref can't let the goal stand, or play an advantage, or even give a free-kick because the ball wasn't in play. However, if he thought that Joe Hart had taken the second touch deliberately to stop Austin getting the ball then he could have booked him for ungentlemanly conduct.
Fantastic ball in. Nightmare for the defence, as illustrated by demichellis! They're having a right go like, fair pmay to QPR