You need to understand Aussie Rules Football to make sense of this article's title, lest you think Dane is in trouble for putting his foot to someone's backside.
A "behind" in the game of "footy" is when you are awarded 1 point for kicking the ball inside either of the outer two goal posts (there are four posts on each end of the oval field). It's also called a "minor" score since the major score of 6 is awarded when you kick the ball between the two inner goal posts.
This historic moment was captured on video. You'll see a kick coming Dane's way (#10) whilst he was playing at the full-forward position. He was unable to catch it in the air, which would be a "mark" and deserving of a free kick. But he did pick the ball up on a bounce after which he was tossed like a rag doll to the ground. They are allowed to tackle, but Dane's opponent was penalised for the manner in which he slung him to the ground earning Dane a free kick. As is the practice, Dane took the ball and backed up about 10 metres, lined up his aim at the goals and kicked away. It was long but slightly off to the right, passing within the outside goal post for a behind.