The AFL has admitted an error was made in awarding Fremantle a controversial goal in its upset four-point win over Collingwood at the MCG on Saturday.

In a statement issued on Sunday afternoon, the League blamed technical issues for the mistake, revealing the score review officer didn't have access to key footage at the time.

In a major talking point, Fremantle star Michael Walters' snap in the third term was deemed a goal by the goal umpire.

A subsequent score review upheld this decision, despite footage showing that the ball had been touched off Walters' boot by Magpie Chris Mayne.

"The score review officer reviewed the vision available at the time and based on this vision supported the umpire's decision that a goal had been scored," the AFL explained.

"Due to technical reasons, the subsequent vision shown by the broadcaster was unavailable to the score review officer at the time of review.

"The AFL acknowledges that based on the additional broadcast vision the ball was touched by Collingwood player Chris Mayne.

"The AFL will continue to improve the score review process to ensure that all vision captured by the broadcaster is available to score review officers at the time of the review."

Walters' goal levelled the scores and he ultimately kicked the match-winning goal in the final minute of play to sink the second-placed Pies.

Collingwood coach Nathan Buckley refused to blame the error for his team's defeat, saying the Pies didn't deserve to win after being outplayed by Ross Lyon's men.

"There didn't seem to be a really thorough review on it, so the umpires were either really clear on it that it wasn't touched or it wasn't looked at externally. I'm not sure why it wasn't looked at closer," Buckley said post-match.

"It's probably a bit topical right now, isn't it? We didn't deserve to win today so you guys can look at the minutiae for me."

Meanwhile, Lyon was philosophical about the incident.

"The space I sit in is you get the rub of the green and you don't get the rub of the green," he said.

"I haven't reviewed it. I don't know. When I was a kid my dad said the umpire's call is final. That's in the vault, it's never going to be changed."