"He should be proud of his team and what they came back from. He just needs to cool himself down - he does say some odd things.
"I thought the ref handled (the Retallick tackle) absolutely perfectly, the bloke was trying to get up. Michael Cheika just needs to learn to put a lid on it."
Slack said Cheika had "got his team up, 100pc improved from the week before."
"Last week they showed no character...last night Wallaby fans saw character," Slack said.
The Australian rugby Hall of Fame member said he was mystified by the All Blacks "who didn't look like the All Blacks for half an hour - it looks like they didn't actually respect Australia. Then they became the All Blacks again."
"It was so surprising - that careless pass from (Damian) McKenzie - I don't know where that was coming from," said Slack.
"It was as if they were playing a touch game against a bunch of rag tags down the road. That's just not what they do."
He said the All Blacks then showed their greatness by getting out of "as deep
a hole as I've ever seen them dig."