Speight looked to have tied the game up at 15-15 in the 44th minute at Eden Park when he ran clear down the righthand touchline.
However, after awarding the try, referee Nigel Owens was alerted to obstruction by Dane Haylett-Petty on All Blacks winger Julian Savea.
After several replays Owens ruled it a no-try for obstruction after discussing the passage of play with TMO Shaun Veldsman.
Former All Blacks first five-eighth Andrew Mehrtens and Wallabies rival George Gregan showed where their loyalties and views lie after the test, taking differing views on the controversial call.
"You can see the argument from both sides," Mehrtens said on the The 'Other Rugby Show on Australian television.
"But I really thought Haylett-Petty was trying to take out Savea.
"You can talk about running the line and support line and whatnot - he ran that line to take out Savea and I think that's worth a penalty."
Gregan, who played 139 tests for Australia, said Haylett-Petty was playing by the rules.
"If you're going to rule the letter of the law that way, you can chase your player into contact and it wasn't going to impact Julian Savea from making that tackle - that's a try," he added on the The 'Other Rugby Show.
"There was still 30 minutes to go, still a lot of rugby to be played and the All Blacks are the best closers in the business.
"But they would have been put under pressure for the first time in that test match, probably for the first time in a very, very long time, they'd have a bit of scoreboard pressure."
The Wallabies didn't score another point in the test, and the All Blacks ran in three tries following the no-try decision.
Former Wallaby Rod Kafer, now part of Fox Sports' commentary team, went as far as saying Owens should never referee again.
In commentary on Fox Sports, and reported by the channel's website, Kafer said he believed Owens had been pressured by the partisan Auckland crowd into reviewing the try.
"This is ridiculous, the crowd's been at the referee and Nigel Owens has now asked for a TMO ruling on a player who's going to be behind the ball and is never, ever in a position to affect the ball," Kafer said in commentary.
"He's been done by the crowd here, Nigel Owens.
"That's shoulder to shoulder, he's behind the ball, there's no such thing as an obstruction.
"Nigel Owens should never referee a test match again, that is disgraceful.
"He's behind the ball, he can run where he likes.
"It was a crucial decision that absolutely changed the course of this test match."