There are too many rules where it's possible to be completely arbitrary about, that being one of them.
With the "sliding rule", no-one knows who the free kick is going to...too many times you think "below the knees" and they give it the other way.
Too many times, the "chopping the arms" is completely ignored, and like yesterday, one gets pulled from somewhere up one umpire's upper intestine. Three umpires let it go, one thinks it's a free, and the others are too gutless to tell him to get back in his box. It wasn't punching the arms, the ball ended in the grandstand.
Advantage call...if players stop, call it back. Of course, I can see how that could be abused where players are coached to stop if they know it's against them.
Toby Greene ducks into a tackle, we're told that constitutes prior opportunity, but they ball it up, and they goal.
I don't even mind the deliberate OOB or deliberate behind rules, but it shouldn't be a free if the ball is escorted out à la Kelly-Simpson early this year. Nor do I mind hands in the back.
And this isn't even mentioning the horrid non-frees to Goddard or Merrett in the last, the awful blocking free against Walla or the non-mark that went 25 metres.