Watching the replay, I'm still wondering how this wasn't a free kick. Unrealistic attempt plus the left arm was over Mansell's shoulder
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You just need to consult the Official AFL Rules MT. I have and outline the relevant extract as follows:
Rule 10.1
It shall be a free kick where a player, whether intentionally or otherwise, makes contact with another player on or above the other player's shoulders.
Rule 10.2
Rule 10.1 does not apply and the umpire shall signal play on where the player infringed wears a guernsey that is black with a yellow sash or yellow with a black sash.