Fans were left fuming and coaches and commentators shocked and confused last night as Sydney's Callum Mills was penalised for a deliberate rushed behind late in the final quarter of the Swans' 23-point loss to the Bulldogs at Etihad Stadium.

Mills punched the ball through the goals from just inside the goal square, with Bulldog Liam Picken hot on his heels.

A free was awarded to the Dogs for a deliberate rushed behind, with Picken slotting the goal from point blank range.

The decision left viewers confused, with Mills seemingly under pressure and within the goal square.

Countless fans took to social media to berate the umpires after the match following several controversial calls.

However, the AFL announced on Saturday morning the correct decision was made regarding the rushed behind.

"AFL has deemed deliberate rushed free in Dogs/Swans as correct under stricter 2017 ruling, due to no physical pressure when ball put over line," official AFL spokesman, Patrick Keane, said.

Bulldogs coach Luke Beveridge admitted post game last night coaches are confused by the interpretation of the rule.

"I think we're all trying to work out what is deliberate and what isn't," Beveridge said.

"I actually wanted a free kick in the goal square because I saw the one in Adelaide last week and I didn't realise it had gone through the points, so I was way off base.

"Whether there's direct pressure or no direct pressure, whether it's before or within that nine metres of the [goal] square, I'm not sure which way it goes. I'm not sure if it's there or if it isn't there."