That reminds me of the match that I refereed where a forward was dribbling the ball, at great pace, down the wing from well - in his own half towards his opponents' goal.
An opponent ran alongside him and clearly elbowed him in the stomach but the attacker was still making great headway and there were no other defenders anywhere around, so I applied the advantage rule and called 'Play on'.
The defender was still running alongside the forward and elbowed him again but, once again, I applied the advantage rule.
Then it happened a third time, and a fourth, and a fifth . . .
I'd called 'play on' around a dozen times before the attacker reached the edge of his opponents' penalty area, still hounded by the defender, with only the goalkeeper to beat. As he ran into the area the defender elbowed him yet again and I immediately awarded a penalty (as it would be easier to beat the keeper 'from the spot' than from where he was, so 'advantage' no longer applied).
Howard Webb (who has run a line for me in his early days!) obviously applied a similar principle. He could see no point in awarding a free-kick outside the box (because it would give the defence time to organise) but as soon as the offence continued into the box he was happy (and correct) to award a penalty.
Chris